diff --git a/app/controllers/admin/application_settings_controller.rb b/app/controllers/admin/application_settings_controller.rb
index 7f7d38a09c580489c6105b591a88d43f60d56683..7c6a444ce7a36ad07be17a5d9b0764e2c7ed78b2 100644
--- a/app/controllers/admin/application_settings_controller.rb
+++ b/app/controllers/admin/application_settings_controller.rb
@@ -237,7 +237,6 @@ def visible_application_setting_attributes
     [
       *::ApplicationSettingsHelper.visible_attributes,
       *::ApplicationSettingsHelper.external_authorization_service_attributes,
-      *ApplicationSetting.repository_storages_weighted_attributes,
       *ApplicationSetting.kroki_formats_attributes.keys.map { |key| "kroki_formats_#{key}".to_sym },
       :lets_encrypt_notification_email,
       :lets_encrypt_terms_of_service_accepted,
@@ -248,8 +247,8 @@ def visible_application_setting_attributes
       :default_branch_name,
       disabled_oauth_sign_in_sources: [],
       import_sources: [],
-      repository_storages: [],
-      restricted_visibility_levels: []
+      restricted_visibility_levels: [],
+      repository_storages_weighted: {}
     ]
   end
 
diff --git a/app/helpers/application_settings_helper.rb b/app/helpers/application_settings_helper.rb
index 244238e246d72bb7c565a4ae98c6115bc9b0ce25..551e08d1e31c0a7a24d9d11bda26e0833314502b 100644
--- a/app/helpers/application_settings_helper.rb
+++ b/app/helpers/application_settings_helper.rb
@@ -37,13 +37,8 @@ def kroki_available_formats
   end
 
   def storage_weights
-    ApplicationSetting.repository_storages_weighted_attributes.map do |attribute|
-      storage = attribute.to_s.delete_prefix('repository_storages_weighted_')
-      {
-        name: attribute,
-        label: storage,
-        value: @application_setting.repository_storages_weighted[storage] || 0
-      }
+    Gitlab.config.repositories.storages.keys.each_with_object(OpenStruct.new) do |storage, weights|
+      weights[storage.to_sym] = @application_setting.repository_storages_weighted[storage] || 0
     end
   end
 
diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index 33c058dab96b47da57dacde2665620daa13f6b23..49666f1a8bd3bce62a9b732240495c4882f0eb96 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -25,10 +25,6 @@ class ApplicationSetting < ApplicationRecord
   alias_attribute :instance_group_id, :instance_administrators_group_id
   alias_attribute :instance_administrators_group, :instance_group
 
-  def self.repository_storages_weighted_attributes
-    @repository_storages_weighted_atributes ||= Gitlab.config.repositories.storages.keys.map { |k| "repository_storages_weighted_#{k}".to_sym }.freeze
-  end
-
   def self.kroki_formats_attributes
     {
       blockdiag: {
@@ -44,7 +40,6 @@ def self.kroki_formats_attributes
   end
 
   store_accessor :kroki_formats, *ApplicationSetting.kroki_formats_attributes.keys, prefix: true
-  store_accessor :repository_storages_weighted, *Gitlab.config.repositories.storages.keys, prefix: true
 
   # Include here so it can override methods from
   # `add_authentication_token_field`
@@ -502,6 +497,7 @@ def self.kroki_formats_attributes
             inclusion: { in: [true, false], message: _('must be a boolean value') }
 
   before_validation :ensure_uuid!
+  before_validation :coerce_repository_storages_weighted, if: :repository_storages_weighted_changed?
 
   before_save :ensure_runners_registration_token
   before_save :ensure_health_check_access_token
@@ -582,12 +578,6 @@ def recaptcha_or_login_protection_enabled
     recaptcha_enabled || login_recaptcha_protection_enabled
   end
 
-  repository_storages_weighted_attributes.each do |attribute|
-    define_method :"#{attribute}=" do |value|
-      super(value.to_i)
-    end
-  end
-
   kroki_formats_attributes.keys.each do |key|
     define_method :"kroki_formats_#{key}=" do |value|
       super(::Gitlab::Utils.to_boolean(value))
diff --git a/app/models/application_setting_implementation.rb b/app/models/application_setting_implementation.rb
index 2911ae6b1c8f362247547d84c92905eee7c17edb..ffbefe91a6ceba1144eadc6b53a9de7103cb1182 100644
--- a/app/models/application_setting_implementation.rb
+++ b/app/models/application_setting_implementation.rb
@@ -293,10 +293,6 @@ def repository_storages
     Array(read_attribute(:repository_storages))
   end
 
-  def repository_storages_weighted
-    read_attribute(:repository_storages_weighted)
-  end
-
   def commit_email_hostname
     super.presence || self.class.default_commit_email_hostname
   end
@@ -328,9 +324,10 @@ def performance_bar_enabled
 
   def normalized_repository_storage_weights
     strong_memoize(:normalized_repository_storage_weights) do
-      weights_total = repository_storages_weighted.values.reduce(:+)
+      repository_storages_weights = repository_storages_weighted.slice(*Gitlab.config.repositories.storages.keys)
+      weights_total = repository_storages_weights.values.reduce(:+)
 
-      repository_storages_weighted.transform_values do |w|
+      repository_storages_weights.transform_values do |w|
         next w if weights_total == 0
 
         w.to_f / weights_total
@@ -468,16 +465,20 @@ def check_repository_storages
       invalid.empty?
   end
 
+  def coerce_repository_storages_weighted
+    repository_storages_weighted.transform_values!(&:to_i)
+  end
+
   def check_repository_storages_weighted
     invalid = repository_storages_weighted.keys - Gitlab.config.repositories.storages.keys
-    errors.add(:repository_storages_weighted, "can't include: %{invalid_storages}" % { invalid_storages: invalid.join(", ") }) unless
+    errors.add(:repository_storages_weighted, _("can't include: %{invalid_storages}") % { invalid_storages: invalid.join(", ") }) unless
       invalid.empty?
 
     repository_storages_weighted.each do |key, val|
       next unless val.present?
 
-      errors.add(:"repository_storages_weighted_#{key}", "value must be an integer") unless val.is_a?(Integer)
-      errors.add(:"repository_storages_weighted_#{key}", "value must be between 0 and 100") unless val.between?(0, 100)
+      errors.add(:repository_storages_weighted, _("value for '%{storage}' must be an integer") % { storage: key }) unless val.is_a?(Integer)
+      errors.add(:repository_storages_weighted, _("value for '%{storage}' must be between 0 and 100") % { storage: key }) unless val.between?(0, 100)
     end
   end
 
diff --git a/app/views/admin/application_settings/_repository_storage.html.haml b/app/views/admin/application_settings/_repository_storage.html.haml
index 0862d1bf0b6e8b438f194024f7b64bd420c76a01..437189cf47f01370d52d1aa4eebe47b000c3bc15 100644
--- a/app/views/admin/application_settings/_repository_storage.html.haml
+++ b/app/views/admin/application_settings/_repository_storage.html.haml
@@ -18,8 +18,9 @@
             = _('Enter weights for storages for new repositories.')
             = link_to sprite_icon('question-o'), help_page_path('administration/repository_storage_paths')
         .form-check
-          - storage_weights.each do |attribute|
-            = f.text_field attribute[:name], class: 'form-text-input', value: attribute[:value]
-            = f.label attribute[:label], attribute[:label], class: 'label-bold form-check-label'
-            %br
+          = f.fields_for :repository_storages_weighted, storage_weights do |storage_form|
+            - Gitlab.config.repositories.storages.keys.each do |storage|
+              = storage_form.text_field storage, class: 'form-text-input'
+              = storage_form.label storage, storage, class: 'label-bold form-check-label'
+              %br
   = f.submit _('Save changes'), class: "gl-button btn btn-success qa-save-changes-button"
diff --git a/changelogs/unreleased/fix_repo_storage_weights_admin.yml b/changelogs/unreleased/fix_repo_storage_weights_admin.yml
new file mode 100644
index 0000000000000000000000000000000000000000..c82ef578e018dbb44d3e752209fab3cf4827f8d0
--- /dev/null
+++ b/changelogs/unreleased/fix_repo_storage_weights_admin.yml
@@ -0,0 +1,5 @@
+---
+title: Allow saving repository weights after a storage has been removed
+merge_request: 53803
+author:
+type: fixed
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index bc98ce39dd72eac28d0026857b0bd2b9ae5610bb..8787f71b9f36d4c82e5fb876c9a9842bc684582a 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -34882,6 +34882,9 @@ msgstr ""
 msgid "can't be enabled because signed commits are required for this project"
 msgstr ""
 
+msgid "can't include: %{invalid_storages}"
+msgstr ""
+
 msgid "cannot be a date in the past"
 msgstr ""
 
@@ -36288,6 +36291,12 @@ msgstr ""
 msgid "v%{version} published %{timeAgo}"
 msgstr ""
 
+msgid "value for '%{storage}' must be an integer"
+msgstr ""
+
+msgid "value for '%{storage}' must be between 0 and 100"
+msgstr ""
+
 msgid "verify ownership"
 msgstr ""
 
diff --git a/spec/controllers/admin/application_settings_controller_spec.rb b/spec/controllers/admin/application_settings_controller_spec.rb
index 71abf3191b89f3992508bbfc1868c42da44a3e67..2b562e2dd64efafa5e574aa28f649786ccc439e6 100644
--- a/spec/controllers/admin/application_settings_controller_spec.rb
+++ b/spec/controllers/admin/application_settings_controller_spec.rb
@@ -144,10 +144,10 @@
     end
 
     it 'updates repository_storages_weighted setting' do
-      put :update, params: { application_setting: { repository_storages_weighted_default: 75 } }
+      put :update, params: { application_setting: { repository_storages_weighted: { default: 75 } } }
 
       expect(response).to redirect_to(general_admin_application_settings_path)
-      expect(ApplicationSetting.current.repository_storages_weighted_default).to eq(75)
+      expect(ApplicationSetting.current.repository_storages_weighted).to eq('default' => 75)
     end
 
     it 'updates kroki_formats setting' do
diff --git a/spec/features/admin/admin_settings_spec.rb b/spec/features/admin/admin_settings_spec.rb
index 52f39f65bd0e9dc9a7061cf087095a5107a0e187..249621f5835ed6e3cb16de91b0111ff2802fbc5a 100644
--- a/spec/features/admin/admin_settings_spec.rb
+++ b/spec/features/admin/admin_settings_spec.rb
@@ -384,7 +384,20 @@
           click_button 'Save changes'
         end
 
-        expect(current_settings.repository_storages_weighted_default).to be 50
+        expect(current_settings.repository_storages_weighted).to eq('default' => 50)
+      end
+
+      it 'still saves when settings are outdated' do
+        current_settings.update_attribute :repository_storages_weighted, { 'default' => 100, 'outdated' => 100 }
+
+        visit repository_admin_application_settings_path
+
+        page.within('.as-repository-storage') do
+          fill_in 'application_setting_repository_storages_weighted_default', with: 50
+          click_button 'Save changes'
+        end
+
+        expect(current_settings.repository_storages_weighted).to eq('default' => 50)
       end
     end
 
diff --git a/spec/helpers/application_settings_helper_spec.rb b/spec/helpers/application_settings_helper_spec.rb
index 2cd01451e0d12c3f310b4e3589cee13929e19ac7..c74ee3ce0ecee95a990667d8fc9142e370397be9 100644
--- a/spec/helpers/application_settings_helper_spec.rb
+++ b/spec/helpers/application_settings_helper_spec.rb
@@ -130,20 +130,15 @@
     before do
       helper.instance_variable_set(:@application_setting, application_setting)
       stub_storage_settings({ 'default': {}, 'storage_1': {}, 'storage_2': {} })
-      allow(ApplicationSetting).to receive(:repository_storages_weighted_attributes).and_return(
-        [:repository_storages_weighted_default,
-         :repository_storages_weighted_storage_1,
-         :repository_storages_weighted_storage_2])
-
       stub_application_setting(repository_storages_weighted: { 'default' => 100, 'storage_1' => 50, 'storage_2' => nil })
     end
 
     it 'returns storages correctly' do
-      expect(helper.storage_weights).to eq([
-          { name: :repository_storages_weighted_default, label: 'default', value: 100 },
-          { name: :repository_storages_weighted_storage_1, label: 'storage_1', value: 50 },
-          { name: :repository_storages_weighted_storage_2, label: 'storage_2', value: 0 }
-        ])
+      expect(helper.storage_weights).to eq(OpenStruct.new(
+                                             default: 100,
+                                             storage_1: 50,
+                                             storage_2: 0
+                                           ))
     end
   end
 
diff --git a/spec/models/application_setting_spec.rb b/spec/models/application_setting_spec.rb
index 8f63f44e8af8355193db71c565589a05ab2dab52..97ed0f5820c76e792b8c75476e70a84548359568 100644
--- a/spec/models/application_setting_spec.rb
+++ b/spec/models/application_setting_spec.rb
@@ -105,14 +105,14 @@
 
     it { is_expected.not_to allow_value(false).for(:hashed_storage_enabled) }
 
-    it { is_expected.not_to allow_value(101).for(:repository_storages_weighted_default) }
-    it { is_expected.to allow_value('90').for(:repository_storages_weighted_default) }
-    it { is_expected.not_to allow_value(-1).for(:repository_storages_weighted_default) }
-    it { is_expected.to allow_value(100).for(:repository_storages_weighted_default) }
-    it { is_expected.to allow_value(0).for(:repository_storages_weighted_default) }
-    it { is_expected.to allow_value(50).for(:repository_storages_weighted_default) }
-    it { is_expected.to allow_value(nil).for(:repository_storages_weighted_default) }
-    it { is_expected.not_to allow_value({ default: 100, shouldntexist: 50 }).for(:repository_storages_weighted) }
+    it { is_expected.to allow_value('default' => 0).for(:repository_storages_weighted) }
+    it { is_expected.to allow_value('default' => 50).for(:repository_storages_weighted) }
+    it { is_expected.to allow_value('default' => 100).for(:repository_storages_weighted) }
+    it { is_expected.to allow_value('default' => '90').for(:repository_storages_weighted) }
+    it { is_expected.to allow_value('default' => nil).for(:repository_storages_weighted) }
+    it { is_expected.not_to allow_value('default' => -1).for(:repository_storages_weighted).with_message("value for 'default' must be between 0 and 100") }
+    it { is_expected.not_to allow_value('default' => 101).for(:repository_storages_weighted).with_message("value for 'default' must be between 0 and 100") }
+    it { is_expected.not_to allow_value('default' => 100, shouldntexist: 50).for(:repository_storages_weighted).with_message("can't include: shouldntexist") }
 
     it { is_expected.to allow_value(400).for(:notes_create_limit) }
     it { is_expected.not_to allow_value('two').for(:notes_create_limit) }
@@ -958,12 +958,6 @@ def expect_invalid
 
   it_behaves_like 'application settings examples'
 
-  describe 'repository_storages_weighted_attributes' do
-    it 'returns the keys for repository_storages_weighted' do
-      expect(subject.class.repository_storages_weighted_attributes).to eq([:repository_storages_weighted_default])
-    end
-  end
-
   describe 'kroki_format_supported?' do
     it 'returns true when Excalidraw is enabled' do
       subject.kroki_formats_excalidraw = true
@@ -1007,11 +1001,4 @@ def expect_invalid
       expect(subject.kroki_formats_excalidraw).to eq(true)
     end
   end
-
-  it 'does not allow to set weight for non existing storage' do
-    setting.repository_storages_weighted = { invalid_storage: 100 }
-
-    expect(setting).not_to be_valid
-    expect(setting.errors.messages[:repository_storages_weighted]).to match_array(["can't include: invalid_storage"])
-  end
 end
diff --git a/spec/support/shared_examples/models/application_setting_shared_examples.rb b/spec/support/shared_examples/models/application_setting_shared_examples.rb
index 92fd436313469a15bcbea46662c8a8c09d88a439..60a02d85a1e9cd8e108e264d5181869b9a422f23 100644
--- a/spec/support/shared_examples/models/application_setting_shared_examples.rb
+++ b/spec/support/shared_examples/models/application_setting_shared_examples.rb
@@ -289,6 +289,7 @@
 
   describe '#pick_repository_storage' do
     before do
+      allow(Gitlab.config.repositories.storages).to receive(:keys).and_return(%w(default backup))
       allow(setting).to receive(:repository_storages_weighted).and_return({ 'default' => 20, 'backup' => 80 })
     end
 
@@ -304,15 +305,19 @@
   describe '#normalized_repository_storage_weights' do
     using RSpec::Parameterized::TableSyntax
 
-    where(:storages, :normalized) do
-      { 'default' => 0, 'backup' => 100 }   | { 'default' => 0.0, 'backup' => 1.0 }
-      { 'default' => 100, 'backup' => 100 } | { 'default' => 0.5, 'backup' => 0.5 }
-      { 'default' => 20, 'backup' => 80 }   | { 'default' => 0.2, 'backup' => 0.8 }
-      { 'default' => 0, 'backup' => 0 }     | { 'default' => 0.0, 'backup' => 0.0 }
+    where(:config_storages, :storages, :normalized) do
+      %w(default backup) | { 'default' => 0, 'backup' => 100 }   | { 'default' => 0.0, 'backup' => 1.0 }
+      %w(default backup) | { 'default' => 100, 'backup' => 100 } | { 'default' => 0.5, 'backup' => 0.5 }
+      %w(default backup) | { 'default' => 20, 'backup' => 80 }   | { 'default' => 0.2, 'backup' => 0.8 }
+      %w(default backup) | { 'default' => 0, 'backup' => 0 }     | { 'default' => 0.0, 'backup' => 0.0 }
+      %w(default)        | { 'default' => 0, 'backup' => 100 }   | { 'default' => 0.0 }
+      %w(default)        | { 'default' => 100, 'backup' => 100 } | { 'default' => 1.0 }
+      %w(default)        | { 'default' => 20, 'backup' => 80 }   | { 'default' => 1.0 }
     end
 
     with_them do
       before do
+        allow(Gitlab.config.repositories.storages).to receive(:keys).and_return(config_storages)
         allow(setting).to receive(:repository_storages_weighted).and_return(storages)
       end
 
diff --git a/spec/views/admin/application_settings/_repository_storage.html.haml_spec.rb b/spec/views/admin/application_settings/_repository_storage.html.haml_spec.rb
index 2915fe1964f52ae87a6dce409c3fc95efe73cd08..dc8f259eb56f9c15ed4ef51a5e5a286234767e9b 100644
--- a/spec/views/admin/application_settings/_repository_storage.html.haml_spec.rb
+++ b/spec/views/admin/application_settings/_repository_storage.html.haml_spec.rb
@@ -3,34 +3,49 @@
 require 'spec_helper'
 
 RSpec.describe 'admin/application_settings/_repository_storage.html.haml' do
-  let(:app_settings) { create(:application_setting) }
-  let(:repository_storages_weighted_attributes) { [:repository_storages_weighted_default, :repository_storages_weighted_mepmep, :repository_storages_weighted_foobar]}
-  let(:repository_storages_weighted) do
-    {
-      "default" => 100,
-      "mepmep" => 50
-    }
-  end
+  let(:app_settings) { build(:application_setting, repository_storages_weighted: repository_storages_weighted) }
 
   before do
-    allow(app_settings).to receive(:repository_storages_weighted).and_return(repository_storages_weighted)
-    allow(app_settings).to receive(:repository_storages_weighted_mepmep).and_return(100)
-    allow(app_settings).to receive(:repository_storages_weighted_foobar).and_return(50)
+    stub_storage_settings({ 'default': {}, 'mepmep': {}, 'foobar': {} })
     assign(:application_setting, app_settings)
-    allow(ApplicationSetting).to receive(:repository_storages_weighted_attributes).and_return(repository_storages_weighted_attributes)
   end
 
-  context 'when multiple storages are available' do
+  context 'additional storage config' do
+    let(:repository_storages_weighted) do
+      {
+        'default' => 100,
+        'mepmep' => 50
+      }
+    end
+
     it 'lists them all' do
       render
 
-      # lists storages that are saved with weights
-      repository_storages_weighted.each do |storage_name, storage_weight|
+      Gitlab.config.repositories.storages.keys.each do |storage_name|
         expect(rendered).to have_content(storage_name)
       end
 
-      # lists storage not saved with weight
       expect(rendered).to have_content('foobar')
     end
   end
+
+  context 'fewer storage configs' do
+    let(:repository_storages_weighted) do
+      {
+        'default' => 100,
+        'mepmep' => 50,
+        'something_old' => 100
+      }
+    end
+
+    it 'lists only configured storages' do
+      render
+
+      Gitlab.config.repositories.storages.keys.each do |storage_name|
+        expect(rendered).to have_content(storage_name)
+      end
+
+      expect(rendered).not_to have_content('something_old')
+    end
+  end
 end