diff --git a/db/docs/batched_background_migrations/backfill_spam_logs_organization_id.yml b/db/docs/batched_background_migrations/backfill_spam_logs_organization_id.yml
new file mode 100644
index 0000000000000000000000000000000000000000..751afb89a3ac94cd4b9a392283a84f0e0ccf6bc5
--- /dev/null
+++ b/db/docs/batched_background_migrations/backfill_spam_logs_organization_id.yml
@@ -0,0 +1,8 @@
+---
+migration_job_name: BackfillSpamLogsOrganizationId
+description: Backfills sharding key `spam_logs.organization_id` from `users`.
+feature_category: instance_resiliency
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/210030
+milestone: '18.6'
+queued_migration_version: 20251023230133
+finalized_by: # version of the migration that finalized this BBM
diff --git a/db/docs/spam_logs.yml b/db/docs/spam_logs.yml
index 6738fe6f613bd6dabec41ec828f81d46555ad35b..7b01568c96641123b8c4900c36db2af12fa77c67 100644
--- a/db/docs/spam_logs.yml
+++ b/db/docs/spam_logs.yml
@@ -19,3 +19,4 @@ desired_sharding_key:
         sharding_key: organization_id
         belongs_to: user
 table_size: small
+desired_sharding_key_migration_job_name: BackfillSpamLogsOrganizationId
diff --git a/db/post_migrate/20251023230133_queue_backfill_spam_logs_organization_id.rb b/db/post_migrate/20251023230133_queue_backfill_spam_logs_organization_id.rb
new file mode 100644
index 0000000000000000000000000000000000000000..80355947681420e7cb273bf5b3d0944ae1f9bdba
--- /dev/null
+++ b/db/post_migrate/20251023230133_queue_backfill_spam_logs_organization_id.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+class QueueBackfillSpamLogsOrganizationId < Gitlab::Database::Migration[2.3]
+  milestone '18.6'
+  restrict_gitlab_migration gitlab_schema: :gitlab_main_org
+
+  MIGRATION = "BackfillSpamLogsOrganizationId"
+  DELAY_INTERVAL = 2.minutes
+  BATCH_SIZE = 1000
+  SUB_BATCH_SIZE = 100
+
+  def up
+    queue_batched_background_migration(
+      MIGRATION,
+      :spam_logs,
+      :id,
+      :organization_id,
+      :users,
+      :organization_id,
+      :user_id,
+      job_interval: DELAY_INTERVAL,
+      batch_size: BATCH_SIZE,
+      sub_batch_size: SUB_BATCH_SIZE
+    )
+  end
+
+  def down
+    delete_batched_background_migration(
+      MIGRATION,
+      :spam_logs,
+      :id,
+      [
+        :organization_id,
+        :users,
+        :organization_id,
+        :user_id
+      ]
+    )
+  end
+end
diff --git a/db/schema_migrations/20251023230133 b/db/schema_migrations/20251023230133
new file mode 100644
index 0000000000000000000000000000000000000000..e2c20d596669e20e235a7f113d1c7bc57942b611
--- /dev/null
+++ b/db/schema_migrations/20251023230133
@@ -0,0 +1 @@
+fda696fcb5d092e2f6a8e3310af7ed0075f4a32978ff3559a5491e4fa2214dcf
\ No newline at end of file
diff --git a/lib/gitlab/background_migration/backfill_spam_logs_organization_id.rb b/lib/gitlab/background_migration/backfill_spam_logs_organization_id.rb
new file mode 100644
index 0000000000000000000000000000000000000000..81557171dab7e613f8e1bbc46e21f20795cb65fa
--- /dev/null
+++ b/lib/gitlab/background_migration/backfill_spam_logs_organization_id.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    class BackfillSpamLogsOrganizationId < BackfillDesiredShardingKeyJob
+      operation_name :backfill_spam_logs_organization_id
+      feature_category :instance_resiliency
+    end
+  end
+end
diff --git a/spec/lib/gitlab/background_migration/backfill_spam_logs_organization_id_spec.rb b/spec/lib/gitlab/background_migration/backfill_spam_logs_organization_id_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..33e47552613b1170e157822b9dffc8f5b5b1eff6
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/backfill_spam_logs_organization_id_spec.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::BackfillSpamLogsOrganizationId, feature_category: :instance_resiliency do
+  include_examples 'desired sharding key backfill job' do
+    let(:batch_table) { :spam_logs }
+    let(:backfill_column) { :organization_id }
+    let(:backfill_via_table) { :users }
+    let(:backfill_via_column) { :organization_id }
+    let(:backfill_via_foreign_key) { :user_id }
+  end
+end
diff --git a/spec/migrations/20251023230133_queue_backfill_spam_logs_organization_id_spec.rb b/spec/migrations/20251023230133_queue_backfill_spam_logs_organization_id_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..20226a2dca890868680280e9ca7548c3059a5923
--- /dev/null
+++ b/spec/migrations/20251023230133_queue_backfill_spam_logs_organization_id_spec.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!
+
+RSpec.describe QueueBackfillSpamLogsOrganizationId, feature_category: :instance_resiliency do
+  let!(:batched_migration) { described_class::MIGRATION }
+
+  it 'schedules a new batched migration' do
+    reversible_migration do |migration|
+      migration.before -> {
+        expect(batched_migration).not_to have_scheduled_batched_migration
+      }
+
+      migration.after -> {
+        expect(batched_migration).to have_scheduled_batched_migration(
+          table_name: :spam_logs,
+          column_name: :id,
+          interval: described_class::DELAY_INTERVAL,
+          batch_size: described_class::BATCH_SIZE,
+          sub_batch_size: described_class::SUB_BATCH_SIZE,
+          gitlab_schema: :gitlab_main_org,
+          job_arguments: [
+            :organization_id,
+            :users,
+            :organization_id,
+            :user_id
+          ]
+        )
+      }
+    end
+  end
+end