diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 8c7d0fa38c..0000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,153 +0,0 @@
-# -*- YAML -*-
-# Copyright (C) 2011 Urabe, Shyouhei.  All rights reserved.
-#
-# This file is  a part of the programming language  Ruby.  Permission is hereby
-# granted,  to either  redistribute  or  modify this  file,  provided that  the
-# conditions  mentioned in  the file  COPYING are  met.  Consult  the  file for
-# details.
-
-# When you see Travis CI issues, or you are interested in understanding how to
-# manage, please check the link below.
-# https://github.com/ruby/ruby/wiki/CI-Servers#travis-ci
-
-# We enable Travis on the specific branches or forked repositories here.
-if: >-
-  (repo != ruby/ruby OR branch = master OR branch =~ /^ruby_\d_\d$/)
-  AND (commit_message !~ /\[DOC\]/)
-
-language: c
-
-os: linux
-
-dist: jammy
-
-git:
-  quiet: true
-
-env:
-  global:
-    - NPROC="$(nproc)"
-    - JOBS="-j${NPROC}"
-    # SETARCH are overridden when necessary. See below.
-    - SETARCH=
-    # https://github.com/travis-ci/travis-build/blob/e411371dda21430a60f61b8f3f57943d2fe4d344/lib/travis/build/bash/travis_apt_get_options.bash#L7
-    - travis_apt_get_options='--allow-downgrades --allow-remove-essential --allow-change-held-packages'
-    - travis_apt_get_options="-yq --no-install-suggests --no-install-recommends $travis_apt_get_options"
-    # -g0 disables backtraces when SEGV. Do not set that.
-    - debugflags=-ggdb3
-    - RUBY_TESTOPTS="$JOBS -q --tty=no"
-
-.org.ruby-lang.ci.matrix-definitions:
-  - &gcc-11
-    compiler: gcc-11
-    before_install:
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - >-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
-        gcc-11
-        g++-11
-        libffi-dev
-        libncurses-dev
-        libncursesw5-dev
-        libreadline-dev
-        libssl-dev
-        libyaml-dev
-        openssl
-        zlib1g-dev
-      - gcc-11 --version
-  - &arm64-linux
-    name: arm64-linux
-    arch: arm64
-    <<: *gcc-11
-  - &ppc64le-linux
-    name: ppc64le-linux
-    arch: ppc64le
-    <<: *gcc-11
-  - &s390x-linux
-    name: s390x-linux
-    arch: s390x
-    <<: *gcc-11
-    env:
-      # Avoid possible test failures with the zlib applying the following patch
-      # on s390x CPU architecture.
-      # https://github.com/madler/zlib/pull/410
-      - DFLTCC=0
-  - &arm32-linux
-    name: arm32-linux
-    arch: arm64
-    # https://packages.ubuntu.com/jammy/crossbuild-essential-armhf
-    compiler: arm-linux-gnueabihf-gcc
-    env:
-      - SETARCH='setarch linux32 --verbose --32bit'
-      # Still keep the -O1 for only arm32, while we want to test with the
-      # default optflags -O3.
-      # Because bootstraptest/test_ractor.rb fails with segfualt with the
-      # default -O3.
-      # https://bugs.ruby-lang.org/issues/19981
-      - optflags=-O1
-    before_install:
-      - sudo dpkg --add-architecture armhf
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - >-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
-        crossbuild-essential-armhf
-        libc6:armhf
-        libstdc++-10-dev:armhf
-        libffi-dev:armhf
-        libncurses-dev:armhf
-        libncursesw5-dev:armhf
-        libreadline-dev:armhf
-        libssl-dev:armhf
-        libyaml-dev:armhf
-        linux-libc-dev:armhf
-        zlib1g-dev:armhf
-
-matrix:
-  include:
-    - <<: *arm64-linux
-    - <<: *ppc64le-linux
-    - <<: *s390x-linux
-    # FIXME: lib/rubygems/util.rb:104 glob_files_in_dir -
-    # <internal:dir>:411:in glob: File name too long - (Errno::ENAMETOOLONG)
-    # https://github.com/rubygems/rubygems/issues/7132
-    - <<: *arm32-linux
-  allow_failures:
-    # The arm64 is very slow to start the jobs.
-    - name: arm64-linux
-    - name: ppc64le-linux
-    - name: s390x-linux
-    # The arm64 is very slow to start the jobs.
-    - name: arm32-linux
-  fast_finish: true
-
-before_script:
-  - lscpu
-  - ./autogen.sh
-  - mkdir build
-  - cd build
-  - $SETARCH ../configure -C --disable-install-doc --prefix=$(pwd)/install
-  - $SETARCH make -s $JOBS
-  - make -s $JOBS install
-  # Useful info to report issues to the Ruby.
-  - $SETARCH $(pwd)/install/bin/ruby -v
-  # Useful info To report issues to the RubyGems.
-  - $SETARCH $(pwd)/install/bin/gem env
-
-script:
-  - $SETARCH make -s test
-  - ../tool/travis_wait.sh $SETARCH make -s test-all RUBYOPT="-w"
-  - ../tool/travis_wait.sh $SETARCH make -s test-spec
-
-# We want to be notified when something happens.
-notifications:
-  webhooks:
-    urls:
-      # ruby-lang slack: ruby/simpler-alerts-bot (travis)
-      - secure: mRsoS/UbqDkKkW5p3AEqM27d4SZnV6Gsylo3bm8T/deltQzTsGzZwrm7OIBXZv0UFZdE68XmPlyHfZFLSP2V9QZ7apXMf9/vw0GtcSe1gchtnjpAPF6lYBn7nMCbVPPx9cS0dwL927fjdRM1vj7IKZ2bk4F0lAJ25R25S6teqdk=
-    on_success: never
-    on_failure: always
-  email:
-    recipients:
-      - jun.aruga@gmail.com
-    on_success: never
-    on_failure: always