diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 818b8ca504..0000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,169 +0,0 @@
-os: linux
-dist: xenial
-
-language: generic
-
-services:
-  - docker
-
-addons:
-  apt:
-    packages:
-      - docker-ce
-
-cache:
-  apt: true
-  directories:
-    - $HOME/.npm
-    - vendor
-
-env:
-  global:
-    - LOCAL_DIR: build
-    - COMPOSER_INSTALL: false
-    - NPM_INSTALL: true
-    - WP_INSTALL: true
-    - PHP_FPM_UID: "`id -u`"
-    - PHP_FPM_GID: "`id -g`"
-    - PUPPETEER_SKIP_CHROMIUM_DOWNLOAD: true
-
-jobs:
-  include:
-  - env: WP_TRAVISCI=test:e2e LOCAL_PHPUNIT=latest PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=
-    name: E2E Tests
-  - env: WP_TRAVISCI=lint:php COMPOSER_INSTALL=true NPM_INSTALL=false WP_INSTALL=false
-    name: PHP Linting
-  - env: WP_TRAVISCI=test:compat COMPOSER_INSTALL=true NPM_INSTALL=false WP_INSTALL=false
-    name: "PHP Compatibility Check"
-  - env: WP_TRAVISCI=travis:js WP_INSTALL=false PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=
-    name: JS Tests
-  - env: LOCAL_PHP=8.0-fpm LOCAL_PHPUNIT=8.0-fpm COMPOSER_INSTALL=true WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 8.0"
-    script:
-      # The PHPUnit 7.x phar is not compatible with PHP 8 and won't be updated,
-      # as PHPUnit 7 is no longer supported, so run the Composer-installed PHPUnit instead.
-      - npm run test:php-composer -- --verbose -c phpunit.xml.dist
-      - npm run test:php-composer -- --verbose -c phpunit.xml.dist --group ajax
-      - npm run test:php-composer -- --verbose -c tests/phpunit/multisite.xml
-      - npm run test:php-composer -- --verbose -c tests/phpunit/multisite.xml --group ms-files
-      - npm run test:php-composer -- --verbose -c phpunit.xml.dist --group external-http
-      - npm run test:php-composer -- --verbose -c phpunit.xml.dist --group restapi-jsclient
-      # __fakegroup__ is excluded to force PHPUnit to ignore the <exclude> settings in phpunit.xml.dist.
-      # Xdebug supports PHP 8 only from version 3.0, which is not released yet.
-      # Once Xdebug 3.0 is released and included in the Docker image, this should be uncommented again.
-      # - LOCAL_PHP_XDEBUG=true docker-compose run --rm phpunit phpunit -v --group xdebug --exclude-group __fakegroup__
-
-  - env: LOCAL_PHP=7.4-fpm LOCAL_PHPUNIT=7.4-fpm WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 7.4"
-  - env: LOCAL_PHP=7.3-fpm LOCAL_PHPUNIT=7.3-fpm WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 7.3"
-  - env: LOCAL_PHP=7.3-fpm LOCAL_PHPUNIT=7.3-fpm LOCAL_PHP_MEMCACHED=true WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 7.3 with Memcached"
-  - env: LOCAL_PHP=7.2-fpm LOCAL_PHPUNIT=7.2-fpm WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 7.2"
-  - env: LOCAL_PHP=7.1-fpm LOCAL_PHPUNIT=7.1-fpm WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 7.1"
-  - env: LOCAL_PHP=7.0-fpm LOCAL_PHPUNIT=7.0-fpm WP_TEST_REPORTER=true WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 7.0"
-  - env: LOCAL_PHP=5.6-fpm LOCAL_PHPUNIT=5.6-fpm WP_TRAVISCI=test:php
-    name: "PHPUnit Tests: PHP 5.6"
-  allow_failures:
-  fast_finish: true
-
-before_install:
-- |
-  if [[ "$WP_TRAVISCI" == "test:php" ]]; then
-      travis_retry svn checkout -r 2387243 https://plugins.svn.wordpress.org/wordpress-importer/trunk/ tests/phpunit/data/plugins/wordpress-importer
-  fi
-- |
-  sudo rm /usr/local/bin/docker-compose
-  curl -L https://github.com/docker/compose/releases/download/1.24.0/docker-compose-`uname -s`-`uname -m` > docker-compose
-  chmod +x docker-compose
-  sudo mv docker-compose /usr/local/bin
-
-before_script:
-- |
-  if [[ "$COMPOSER_INSTALL" == "true" && ${LOCAL_PHP:0:3} != "8.0" ]]; then
-    docker-compose run --rm php composer --version
-    docker-compose run --rm php composer install
-  elif [[ "$COMPOSER_INSTALL" == "true" && ${LOCAL_PHP:0:3} == "8.0" ]]; then
-    docker-compose run --rm php composer --version
-    docker-compose run --rm php composer install --ignore-platform-reqs
-  fi
-- npm --version
-- node --version
-- nvm install --latest-npm
-- |
-  if [[ "$NPM_INSTALL" == "true" ]]; then
-    npm ci
-  fi
-- |
-  if [[ "$WP_TRAVISCI" == "test:e2e" ]] || [[ "$WP_TRAVISCI" == "test:php" ]]; then
-    npm run env:start
-    npm run build
-    docker-compose run --rm mysql mysql --version
-    docker-compose run --rm php php --version
-    docker-compose run --rm php php -m
-  fi
-- |
-  if [[ ${LOCAL_PHP:0:3} == "8.0" ]]; then
-    docker-compose run --rm phpunit php ./vendor/bin/phpunit --version
-  elif [[ "$WP_TRAVISCI" == "test:e2e" ]] || [[ "$WP_TRAVISCI" == "test:php" ]]; then
-    docker-compose run --rm phpunit phpunit --version
-  fi
-- |
-  if [[ "$LOCAL_PHP_MEMCACHED" == "true" ]]; then
-    cp tests/phpunit/includes/object-cache.php build/wp-content/object-cache.php
-    # The memcached server needs to start after `npm run env:start`, which sets up the Docker network.
-    docker run --name memcached --net $(basename "$PWD")_wpdevnet -d memcached
-  fi
-- |
-  if [[ "$WP_INSTALL" == "true" ]]; then
-    # Run the install process after memcached has started.
-    npm run env:install
-  fi
-- npm --version
-- node --version
-- curl --version
-- git --version
-- svn --version
-- php --version
-- php -i
-- locale -a
-
-script:
-  - |
-    if [[ "$WP_TRAVISCI" == "test:e2e" ]]; then
-      npm run test:e2e
-    elif [[ "$WP_TRAVISCI" == "test:php" ]]; then
-      npm run test:php -- --verbose -c phpunit.xml.dist &&
-      npm run test:php -- --verbose -c phpunit.xml.dist --group ajax &&
-      npm run test:php -- --verbose -c tests/phpunit/multisite.xml &&
-      npm run test:php -- --verbose -c tests/phpunit/multisite.xml --group ms-files &&
-      npm run test:php -- --verbose -c phpunit.xml.dist --group external-http &&
-      npm run test:php -- --verbose -c phpunit.xml.dist --group restapi-jsclient &&
-      # __fakegroup__ is excluded to force PHPUnit to ignore the <exclude> settings in phpunit.xml.dist.
-      LOCAL_PHP_XDEBUG=true npm run test:php -- -v --group xdebug --exclude-group __fakegroup__
-    elif [[ "$WP_TRAVISCI" == "lint:php" ]]; then
-      docker-compose run --rm php composer lint:errors &&
-      docker-compose run --rm php composer lint tests
-    elif [[ "$WP_TRAVISCI" == "test:compat" ]]; then
-      docker-compose run --rm php composer compat
-    else
-      npm run grunt $WP_TRAVISCI
-    fi
-
-after_script:
-- |
-  if [[ "$WP_TEST_REPORTER" == "true" ]]; then
-    git clone https://github.com/WordPress/phpunit-test-runner.git test-runner
-    docker-compose run --rm -e WPT_REPORT_API_KEY -e WPT_PREPARE_DIR=/var/www -e WPT_TEST_DIR=/var/www php php test-runner/report.php
-  fi
-
-notifications:
-  slack:
-    rooms:
-      secure: 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
-    on_failure: always
-    on_success: change
-    on_pull_requests: false