diff --git a/changelogs/unreleased/dz-remove-legacy-routes.yml b/changelogs/unreleased/dz-remove-legacy-routes.yml
new file mode 100644
index 0000000000000000000000000000000000000000..9233df748532abd0bf1164d67e93acb3a3ccb9b1
--- /dev/null
+++ b/changelogs/unreleased/dz-remove-legacy-routes.yml
@@ -0,0 +1,5 @@
+---
+title: Remove project routes that were deprecated before 12.1
+merge_request: 26808
+author:
+type: removed
diff --git a/config/routes/project.rb b/config/routes/project.rb
index 67afbe5e7f594c62223048967ab9def89db15a23..a4bfac4a5f0444c5477e1e1faab1329ce5082b8b 100644
--- a/config/routes/project.rb
+++ b/config/routes/project.rb
@@ -475,11 +475,7 @@
       # Legacy routes.
       # Introduced in 12.0.
       # Should be removed with https://gitlab.com/gitlab-org/gitlab/issues/28848.
-      Gitlab::Routing.redirect_legacy_paths(self, :settings, :branches, :tags,
-                                            :network, :graphs, :autocomplete_sources,
-                                            :project_members, :deploy_keys, :deploy_tokens,
-                                            :labels, :milestones, :services, :boards, :releases,
-                                            :forks, :group_links, :import, :avatar, :mirror,
+      Gitlab::Routing.redirect_legacy_paths(self, :mirror,
                                             :cycle_analytics, :mattermost, :variables, :triggers,
                                             :environments, :protected_environments, :error_tracking, :alert_management,
                                             :serverless, :clusters, :audit_events, :wikis, :merge_requests,
diff --git a/spec/routing/project_routing_spec.rb b/spec/routing/project_routing_spec.rb
index fd6cccba959fb6fb94a58dede17cebf05c7df705..c8ea0e35cf183145f5f876f5f31b784b99848637 100644
--- a/spec/routing/project_routing_spec.rb
+++ b/spec/routing/project_routing_spec.rb
@@ -143,8 +143,6 @@
         expect(get("/gitlab/gitlabhq/-/autocomplete_sources/#{action}")).to route_to("projects/autocomplete_sources##{action}", namespace_id: 'gitlab', project_id: 'gitlabhq')
       end
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/autocomplete_sources/labels", "/gitlab/gitlabhq/-/autocomplete_sources/labels"
   end
 
   #  pages_project_wikis GET    /:project_id/wikis/pages(.:format)       projects/wikis#pages
@@ -220,8 +218,6 @@
       expect(delete('/gitlab/gitlabhq/-/branches/feature%2B45/foo/bar/baz')).to route_to('projects/branches#destroy', namespace_id: 'gitlab', project_id: 'gitlabhq', id: 'feature+45/foo/bar/baz')
       expect(delete('/gitlab/gitlabhq/-/branches/feature@45/foo/bar/baz')).to route_to('projects/branches#destroy', namespace_id: 'gitlab', project_id: 'gitlabhq', id: 'feature@45/foo/bar/baz')
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/branches", "/gitlab/gitlabhq/-/branches"
   end
 
   describe Projects::TagsController, 'routing' do
@@ -249,8 +245,6 @@
       let(:controller) { 'deploy_keys' }
       let(:controller_path) { '/-/deploy_keys' }
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/deploy_keys", "/gitlab/gitlabhq/-/deploy_keys"
   end
 
   # project_protected_branches GET    /:project_id/protected_branches(.:format)     protected_branches#index
@@ -487,7 +481,6 @@
       let(:controller_path) { '/-/project_members' }
     end
 
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/project_members", "/gitlab/gitlabhq/-/project_members"
     it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/-/settings/members", "/gitlab/gitlabhq/-/project_members"
   end
 
@@ -509,8 +502,6 @@
     it 'to #promote' do
       expect(post('/gitlab/gitlabhq/-/milestones/1/promote')).to route_to('projects/milestones#promote', namespace_id: 'gitlab', project_id: 'gitlabhq', id: "1")
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/milestones", "/gitlab/gitlabhq/-/milestones"
   end
 
   # project_labels GET    /:project_id/labels(.:format) labels#index
@@ -518,8 +509,6 @@
     it 'to #index' do
       expect(get('/gitlab/gitlabhq/-/labels')).to route_to('projects/labels#index', namespace_id: 'gitlab', project_id: 'gitlabhq')
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/labels", "/gitlab/gitlabhq/-/labels"
   end
 
   #        sort_project_issues POST   /:project_id/issues/sort(.:format)        issues#sort
@@ -719,8 +708,6 @@
       expect(get('/gitlab/gitlabhq/-/network/ends-with.json')).to route_to('projects/network#show', namespace_id: 'gitlab', project_id: 'gitlabhq', id: 'ends-with.json')
       expect(get('/gitlab/gitlabhq/-/network/master?format=json')).to route_to('projects/network#show', namespace_id: 'gitlab', project_id: 'gitlabhq', id: 'master', format: 'json')
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/network/master", "/gitlab/gitlabhq/-/network/master"
   end
 
   describe Projects::GraphsController, 'routing' do
@@ -729,8 +716,6 @@
       expect(get('/gitlab/gitlabhq/-/graphs/ends-with.json')).to route_to('projects/graphs#show', namespace_id: 'gitlab', project_id: 'gitlabhq', id: 'ends-with.json')
       expect(get('/gitlab/gitlabhq/-/graphs/master?format=json')).to route_to('projects/graphs#show', namespace_id: 'gitlab', project_id: 'gitlabhq', id: 'master', format: 'json')
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/graphs/master", "/gitlab/gitlabhq/-/graphs/master"
   end
 
   describe Projects::ForksController, 'routing' do
@@ -741,8 +726,6 @@
     it 'to #create' do
       expect(post('/gitlab/gitlabhq/-/forks')).to route_to('projects/forks#create', namespace_id: 'gitlab', project_id: 'gitlabhq')
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/forks", "/gitlab/gitlabhq/-/forks"
   end
 
   # project_avatar DELETE /project/avatar(.:format) projects/avatars#destroy
@@ -751,8 +734,6 @@
       expect(delete('/gitlab/gitlabhq/-/avatar')).to route_to(
         'projects/avatars#destroy', namespace_id: 'gitlab', project_id: 'gitlabhq')
     end
-
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/avatar", "/gitlab/gitlabhq/-/avatar"
   end
 
   describe Projects::PagesDomainsController, 'routing' do
@@ -798,8 +779,6 @@
       expect(get('/gitlab/gitlabhq/-/settings/repository')).to route_to('projects/settings/repository#show', namespace_id: 'gitlab', project_id: 'gitlabhq')
     end
 
-    it_behaves_like 'redirecting a legacy project path', "/gitlab/gitlabhq/settings/repository", "/gitlab/gitlabhq/-/settings/repository"
-
     it 'to repository#create_deploy_token' do
       expect(post('gitlab/gitlabhq/-/settings/ci_cd/deploy_token/create')).to route_to('projects/settings/repository#create_deploy_token', namespace_id: 'gitlab', project_id: 'gitlabhq')
     end