diff --git a/source/ci_source/providers/GitLabCI.ts b/source/ci_source/providers/GitLabCI.ts
new file mode 100644
index 000000000..a9343bf22
--- /dev/null
+++ b/source/ci_source/providers/GitLabCI.ts
@@ -0,0 +1,68 @@
+import { Env, CISource } from "../ci_source"
+import { ensureEnvKeysExist, ensureEnvKeysAreInt } from "../ci_source_helpers"
+
+export class GitLabCI implements CISource {
+  constructor(private readonly env: Env) {}
+
+  get name(): string {
+    return "GitLab CI"
+  }
+
+  get isCI(): boolean {
+    return ensureEnvKeysExist(this.env, ["CI_MR_ID"])
+  }
+
+  get isPR(): boolean {
+    const mustHave = ["CI_MR_ID", "CI_PROJECT_PATH"]
+    const mustBeInts = ["CI_MR_ID"]
+    return ensureEnvKeysExist(this.env, mustHave) && ensureEnvKeysAreInt(this.env, mustBeInts)
+  }
+
+  get pullRequestID(): string {
+    return this.env.CI_MR_ID
+  }
+
+  get repoSlug(): string {
+    return this.env.CI_PROJECT_PATH
+  }
+}
+
+// See https://docs.gitlab.com/ee/ci/variables/
+//
+// export CI_JOB_ID="50"
+// export CI_COMMIT_SHA="1ecfd275763eff1d6b4844ea3168962458c9f27a"
+// export CI_COMMIT_SHORT_SHA="1ecfd275"
+// export CI_COMMIT_REF_NAME="master"
+// export CI_REPOSITORY_URL="https://gitlab-ci-token:abcde-1234ABCD5678ef@example.com/gitlab-org/gitlab-ce.git"
+// export CI_COMMIT_TAG="1.0.0"
+// export CI_JOB_NAME="spec:other"
+// export CI_JOB_STAGE="test"
+// export CI_JOB_MANUAL="true"
+// export CI_JOB_TRIGGERED="true"
+// export CI_JOB_TOKEN="abcde-1234ABCD5678ef"
+// export CI_PIPELINE_ID="1000"
+// export CI_PIPELINE_IID="10"
+// export CI_PAGES_DOMAIN="gitlab.io"
+// export CI_PAGES_URL="https://gitlab-org.gitlab.io/gitlab-ce"
+// export CI_PROJECT_ID="34"
+// export CI_PROJECT_DIR="/builds/gitlab-org/gitlab-ce"
+// export CI_PROJECT_NAME="gitlab-ce"
+// export CI_PROJECT_NAMESPACE="gitlab-org"
+// export CI_PROJECT_PATH="gitlab-org/gitlab-ce"
+// export CI_PROJECT_URL="https://example.com/gitlab-org/gitlab-ce"
+// export CI_REGISTRY="registry.example.com"
+// export CI_REGISTRY_IMAGE="registry.example.com/gitlab-org/gitlab-ce"
+// export CI_RUNNER_ID="10"
+// export CI_RUNNER_DESCRIPTION="my runner"
+// export CI_RUNNER_TAGS="docker, linux"
+// export CI_SERVER="yes"
+// export CI_SERVER_NAME="GitLab"
+// export CI_SERVER_REVISION="70606bf"
+// export CI_SERVER_VERSION="8.9.0"
+// export CI_SERVER_VERSION_MAJOR="8"
+// export CI_SERVER_VERSION_MINOR="9"
+// export CI_SERVER_VERSION_PATCH="0"
+// export GITLAB_USER_ID="42"
+// export GITLAB_USER_EMAIL="user@example.com"
+// export CI_REGISTRY_USER="gitlab-ci-token"
+// export CI_REGISTRY_PASSWORD="longalfanumstring"
diff --git a/source/ci_source/providers/index.ts b/source/ci_source/providers/index.ts
index 88204abe9..94828b3a7 100644
--- a/source/ci_source/providers/index.ts
+++ b/source/ci_source/providers/index.ts
@@ -9,6 +9,7 @@ import { DockerCloud } from "./DockerCloud"
 import { Drone } from "./Drone"
 import { FakeCI } from "./Fake"
 import { GitHubActions } from "./GitHubActions"
+import { GitLabCI } from "./GitLabCI"
 import { Jenkins } from "./Jenkins"
 import { Netlify } from "./Netlify"
 import { Nevercode } from "./Nevercode"
@@ -22,6 +23,7 @@ import { VSTS } from "./VSTS"
 const providers = [
   FakeCI,
   GitHubActions,
+  GitLabCI,
   Travis,
   Circle,
   Semaphore,
@@ -45,6 +47,7 @@ const providers = [
 // Mainly used for Dangerfile linting
 const realProviders = [
   GitHubActions,
+  GitLabCI,
   Travis,
   Circle,
   Semaphore,