diff --git a/.github/workflows/build-pull-request-jenkins.yml b/.github/workflows/build-pull-request-jenkins.yml
new file mode 100644
index 0000000000..68d95d9812
--- /dev/null
+++ b/.github/workflows/build-pull-request-jenkins.yml
@@ -0,0 +1,157 @@
+name: Build Pull Request Jenkins
+
+on:
+  pull_request:
+    paths-ignore:
+      - '.github/**'
+      - 'docs/**'
+      - '!.github/workflows/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  jenkins-ci-docker:
+    runs-on: ubuntu-latest
+    env:
+      JENKINS_URL: ${{ vars.JENKINS_URL || 'https://starjenkins.sdcc.bnl.gov' }}
+      JENKINS_JOB: ${{ vars.JENKINS_JOB || 'star-sw-ci-pipeline' }}
+      JENKINS_USER: ${{ secrets.JENKINS_USER }}
+      JENKINS_TOKEN: ${{ secrets.JENKINS_TOKEN }}
+      PR_NUMBER: ${{ github.event.pull_request.number }}
+      BRANCH_NAME: ${{ github.event.pull_request.head.ref }}
+      GIT_COMMIT: ${{ github.event.pull_request.head.sha }}
+      REPO_URL: ${{ github.event.pull_request.head.repo.clone_url }}
+    steps:
+      - name: Validate Jenkins configuration
+        run: |
+          set -euo pipefail
+          for var in JENKINS_URL JENKINS_JOB JENKINS_USER JENKINS_TOKEN PR_NUMBER BRANCH_NAME GIT_COMMIT REPO_URL; do
+            if [ -z "${!var:-}" ]; then
+              echo "::error::Missing required value for ${var}"
+              exit 1
+            fi
+          done
+
+      - name: Fetch Jenkins crumb
+        id: crumb
+        run: |
+          set -euo pipefail
+          curl_auth="${JENKINS_USER}:${JENKINS_TOKEN}"
+          crumb="$(curl --silent --show-error --fail --retry 3 --retry-all-errors --user "$curl_auth" \
+            "${JENKINS_URL}/crumbIssuer/api/xml?xpath=concat(//crumbRequestField,%22:%22,//crumb)")"
+          echo "::add-mask::$crumb"
+          echo "value=$crumb" >> "$GITHUB_OUTPUT"
+
+      - name: Cancel older Jenkins builds for this PR
+        env:
+          JENKINS_CRUMB: ${{ steps.crumb.outputs.value }}
+        run: |
+          set -euo pipefail
+          curl_auth="${JENKINS_USER}:${JENKINS_TOKEN}"
+
+          build_api="${JENKINS_URL}/job/${JENKINS_JOB}/api/json?tree=builds[number,url,building,actions[parameters[name,value]]]"
+          queue_api="${JENKINS_URL}/queue/api/json?tree=items[id,task[name],actions[parameters[name,value]]]"
+
+          running_builds="$(
+            curl --globoff --silent --show-error --fail --retry 3 --retry-all-errors --user "$curl_auth" "$build_api" |
+              jq -r --arg pr "$PR_NUMBER" --arg branch "$BRANCH_NAME" --arg repo "$REPO_URL" '
+                def param($name): ([.actions[]?.parameters[]? | select(.name == $name) | (.value | tostring)][0] // "");
+                .builds[]?
+                | select(.building == true)
+                | select(
+                    (param("PR_NUMBER") != "" and param("PR_NUMBER") == $pr)
+                    or
+                    (param("PR_NUMBER") == "" and param("BRANCH_NAME") == $branch and param("REPO_URL") == $repo)
+                  )
+                | .url
+              '
+          )"
+
+          queued_items="$(
+            curl --globoff --silent --show-error --fail --retry 3 --retry-all-errors --user "$curl_auth" "$queue_api" |
+              jq -r --arg job "$JENKINS_JOB" --arg pr "$PR_NUMBER" --arg branch "$BRANCH_NAME" --arg repo "$REPO_URL" '
+                def param($name): ([.actions[]?.parameters[]? | select(.name == $name) | (.value | tostring)][0] // "");
+                .items[]?
+                | select(.task.name == $job)
+                | select(
+                    (param("PR_NUMBER") != "" and param("PR_NUMBER") == $pr)
+                    or
+                    (param("PR_NUMBER") == "" and param("BRANCH_NAME") == $branch and param("REPO_URL") == $repo)
+                  )
+                | .id
+              '
+          )"
+
+          if [ -n "$queued_items" ]; then
+            while IFS= read -r item_id; do
+              [ -n "$item_id" ] || continue
+              echo "Canceling queued Jenkins item ${item_id}"
+              curl --silent --show-error --fail \
+                --request POST \
+                --retry 3 \
+                --retry-all-errors \
+                --user "$curl_auth" \
+                --header "$JENKINS_CRUMB" \
+                --output /dev/null \
+                "${JENKINS_URL}/queue/cancelItem?id=${item_id}"
+            done <<< "$queued_items"
+          fi
+
+          if [ -n "$running_builds" ]; then
+            while IFS= read -r build_url; do
+              [ -n "$build_url" ] || continue
+              echo "Stopping running Jenkins build ${build_url}"
+              curl --silent --show-error --fail \
+                --request POST \
+                --retry 3 \
+                --retry-all-errors \
+                --user "$curl_auth" \
+                --header "$JENKINS_CRUMB" \
+                --output /dev/null \
+                "${build_url}stop"
+            done <<< "$running_builds"
+          fi
+
+      - name: Trigger Jenkins docker job
+        env:
+          JENKINS_CRUMB: ${{ steps.crumb.outputs.value }}
+        run: |
+          set -euo pipefail
+          curl_auth="${JENKINS_USER}:${JENKINS_TOKEN}"
+          response_headers="$(mktemp)"
+
+          curl --silent --show-error --fail \
+            --request POST \
+            --retry 3 \
+            --retry-all-errors \
+            --user "$curl_auth" \
+            --header "$JENKINS_CRUMB" \
+            --data-urlencode "PR_NUMBER=${PR_NUMBER}" \
+            --data-urlencode "BRANCH_NAME=${BRANCH_NAME}" \
+            --data-urlencode "GIT_COMMIT=${GIT_COMMIT}" \
+            --data-urlencode "REPO_URL=${REPO_URL}" \
+            --dump-header "$response_headers" \
+            --output /dev/null \
+            "${JENKINS_URL}/job/${JENKINS_JOB}/buildWithParameters"
+
+          queue_url="$(awk 'BEGIN {IGNORECASE=1} /^Location:/ {print $2}' "$response_headers" | tr -d '\r')"
+
+          echo "Triggered Jenkins job ${JENKINS_JOB} for ${BRANCH_NAME}@${GIT_COMMIT}"
+          if [ -n "$queue_url" ]; then
+            echo "Queue item: ${queue_url}"
+            {
+              echo "### Jenkins Triggered"
+              echo
+              echo "- Job: \`${JENKINS_JOB}\`"
+              echo "- Pull request: \`${PR_NUMBER}\`"
+              echo "- Branch: \`${BRANCH_NAME}\`"
+              echo "- Commit: \`${GIT_COMMIT}\`"
+              echo "- Queue item: ${queue_url}"
+            } >> "$GITHUB_STEP_SUMMARY"
+          fi
diff --git a/.github/workflows/build-pull-request.yml b/.github/workflows/build-pull-request.yml
index 6f5b6756dc..afa7f4d7f7 100644
--- a/.github/workflows/build-pull-request.yml
+++ b/.github/workflows/build-pull-request.yml
@@ -13,6 +13,9 @@ concurrency:
 
 jobs:
   build:
+    # Temporary guard while validating the Jenkins-backed PR workflow on the
+    # `jenkins-ci-pipeline` branch without running the normal Docker build matrix.
+    if: github.event.pull_request.head.ref != 'jenkins-ci-pipeline'
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -42,6 +45,7 @@ jobs:
           path: /tmp/star-sw-${{ env.STARENV }}.tar
 
   test:
+    if: github.event.pull_request.head.ref != 'jenkins-ci-pipeline'
     runs-on: ubuntu-latest
     needs: build
     strategy:
@@ -68,6 +72,7 @@ jobs:
                sh -c "set -e; MALLOC_CHECK_=3 $TEST_CMD 2>&1 | tee log; grep 'Run completed' log"
 
   ROOT5_test_doEvents:
+    if: github.event.pull_request.head.ref != 'jenkins-ci-pipeline'
     runs-on: ubuntu-latest
     needs: build
     strategy:
@@ -93,6 +98,7 @@ jobs:
                sh -c "set -e; $TEST_CMD 2>&1 | tee log;  grep '<StIOMaker::Finish> IO:' log"
 
   ROOT5_test_find_vertex:
+    if: github.event.pull_request.head.ref != 'jenkins-ci-pipeline'
     runs-on: ubuntu-latest
     needs: build
     strategy:
diff --git a/Jenkinsfile b/Jenkinsfile
new file mode 100644
index 0000000000..5e9a48493e
--- /dev/null
+++ b/Jenkinsfile
@@ -0,0 +1,114 @@
+pipeline {
+  agent none
+
+  options {
+    timestamps()
+    skipDefaultCheckout(true)
+    parallelsAlwaysFailFast()
+  }
+
+  parameters {
+    string(name: 'PR_NUMBER', defaultValue: '', description: 'Pull request number, optional')
+    string(name: 'BRANCH_NAME', defaultValue: 'main', description: 'Branch to build')
+    string(name: 'GIT_COMMIT', defaultValue: '', description: 'Commit SHA to build, optional')
+    string(name: 'REPO_URL', defaultValue: 'https://github.com/star-bnl/star-sw.git', description: 'Repository URL')
+  }
+
+  environment {
+    ARTIFACT_DIR = 'artifacts'
+  }
+
+  stages {
+    stage('Build Docker Images') {
+      matrix {
+        agent any
+
+        axes {
+          axis {
+            name 'STAR_BASE'
+            values 'root5', 'root6'
+          }
+          axis {
+            name 'COMPILER'
+            values 'gcc485', 'gcc11'
+          }
+        }
+
+        stages {
+          stage('Checkout') {
+            steps {
+              checkout([
+                $class: 'GitSCM',
+                branches: [[name: "*/${params.BRANCH_NAME}"]],
+                userRemoteConfigs: [[
+                  url: "${params.REPO_URL}",
+                  refspec: '+refs/heads/*:refs/remotes/origin/* +refs/tags/*:refs/tags/*'
+                ]]
+              ])
+            }
+          }
+
+          stage('Checkout exact commit if provided') {
+            when {
+              expression { return params.GIT_COMMIT?.trim() }
+            }
+            steps {
+              sh '''
+                set -euxo pipefail
+                git fetch --all --tags
+                git checkout "${GIT_COMMIT}"
+                git rev-parse HEAD
+              '''
+            }
+          }
+
+          stage('Prepare Docker Buildx') {
+            steps {
+              sh '''
+                set -euxo pipefail
+                command -v docker
+                docker --version
+                docker buildx version
+                docker buildx use default || true
+                docker buildx inspect default --bootstrap || docker buildx inspect --bootstrap
+              '''
+            }
+          }
+
+          stage('Build Docker Image') {
+            steps {
+              sh '''
+                set -euxo pipefail
+                starenv="${STAR_BASE}-${COMPILER}"
+                image_tag="ghcr.io/star-bnl/star-sw-${starenv}"
+                image_tar="${ARTIFACT_DIR}/star-sw-${starenv}.tar"
+
+                mkdir -p "${ARTIFACT_DIR}"
+
+                docker buildx build \
+                  --progress plain \
+                  --build-arg "starenv=${STAR_BASE}" \
+                  --build-arg "compiler=${COMPILER}" \
+                  --tag "${image_tag}" \
+                  --output "type=docker,dest=${image_tar}" \
+                  .
+              '''
+            }
+          }
+
+          stage('Archive Docker Image') {
+            steps {
+              archiveArtifacts artifacts: "artifacts/star-sw-${STAR_BASE}-${COMPILER}.tar", fingerprint: true
+            }
+          }
+        }
+      }
+    }
+  }
+
+  post {
+    always {
+      echo "Build finished: ${currentBuild.currentResult}"
+    }
+  }
+}