diff --git a/app/models/project.rb b/app/models/project.rb
index 446329557d5a71117079726201e623673323ec6b..36bc7659bb2bfa2189c1374e8f44c74834298db6 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -1226,6 +1226,7 @@ class Project < ActiveRecord::Base
       { key: 'CI_PROJECT_ID', value: id.to_s, public: true },
       { key: 'CI_PROJECT_NAME', value: path, public: true },
       { key: 'CI_PROJECT_PATH', value: path_with_namespace, public: true },
+      { key: 'CI_PROJECT_PATH_SLUG', value: path_with_namespace.parameterize, public: true },
       { key: 'CI_PROJECT_NAMESPACE', value: namespace.full_path, public: true },
       { key: 'CI_PROJECT_URL', value: web_url, public: true }
     ]
diff --git a/changelogs/unreleased/31061-26135-ci-project-slug-enviroment-variables.yml b/changelogs/unreleased/31061-26135-ci-project-slug-enviroment-variables.yml
new file mode 100644
index 0000000000000000000000000000000000000000..e71910dbd67d42433e1fea7c03c99a7cb9ec56aa
--- /dev/null
+++ b/changelogs/unreleased/31061-26135-ci-project-slug-enviroment-variables.yml
@@ -0,0 +1,4 @@
+---
+title: Add slugify project path to CI enviroment variables
+merge_request: 11838
+author: Ivan Chernov
diff --git a/doc/ci/variables/README.md b/doc/ci/variables/README.md
index 76ad7c564a3494b7153b4b4a98763ab32c104fb8..ad897d5cf1ac22dbff954274b2495b9566495fa9 100644
--- a/doc/ci/variables/README.md
+++ b/doc/ci/variables/README.md
@@ -56,9 +56,10 @@ future GitLab releases.**
 | **CI_PIPELINE_TRIGGERED**       | all    | all    | The flag to indicate that job was [triggered] |
 | **CI_PROJECT_DIR**              | all    | all    | The full path where the repository is cloned and where the job is run |
 | **CI_PROJECT_ID**               | all    | all    | The unique id of the current project that GitLab CI uses internally |
-| **CI_PROJECT_NAME**             | 8.10   | 0.5    | The project name that is currently being built |
+| **CI_PROJECT_NAME**             | 8.10   | 0.5    | The project name that is currently being built (actually it is project folder name) |
 | **CI_PROJECT_NAMESPACE**        | 8.10   | 0.5    | The project namespace (username or groupname) that is currently being built |
 | **CI_PROJECT_PATH**             | 8.10   | 0.5    | The namespace with project name |
+| **CI_PROJECT_PATH_SLUG**        | 9.3    | all    | `$CI_PROJECT_PATH` lowercased and with everything except `0-9` and `a-z` replaced with `-`. Use in URLs and domain names. |
 | **CI_PROJECT_URL**              | 8.10   | 0.5    | The HTTP address to access project |
 | **CI_REGISTRY**                 | 8.10   | 0.5    | If the Container Registry is enabled it returns the address of GitLab's Container Registry |
 | **CI_REGISTRY_IMAGE**           | 8.10   | 0.5    | If the Container Registry is enabled for the project it returns the address of the registry tied to the specific project |
diff --git a/spec/models/ci/build_spec.rb b/spec/models/ci/build_spec.rb
index e2406290c6c2e2cadff5c63cc1ccc68e4e0ced4e..55bfeb6eb418f927bdbb6ae174f747b3f18cf9d1 100644
--- a/spec/models/ci/build_spec.rb
+++ b/spec/models/ci/build_spec.rb
@@ -1139,6 +1139,7 @@ describe Ci::Build, :models do
         { key: 'CI_PROJECT_ID', value: project.id.to_s, public: true },
         { key: 'CI_PROJECT_NAME', value: project.path, public: true },
         { key: 'CI_PROJECT_PATH', value: project.full_path, public: true },
+        { key: 'CI_PROJECT_PATH_SLUG', value: project.full_path.parameterize, public: true },
         { key: 'CI_PROJECT_NAMESPACE', value: project.namespace.full_path, public: true },
         { key: 'CI_PROJECT_URL', value: project.web_url, public: true },
         { key: 'CI_PIPELINE_ID', value: pipeline.id.to_s, public: true },