diff --git a/_data/branches.yml b/_data/branches.yml
index 7b59c738ea..7a28506946 100644
--- a/_data/branches.yml
+++ b/_data/branches.yml
@@ -8,6 +8,11 @@
 #   date:     date of first stable release (YYYY-MM-DD)
 #   eol_date: date of EOL (YYYY-MM-DD)
 
+- name: 4.1
+  status: preview
+  date:
+  eol_date:
+
 - name: 4.0
   status: normal maintenance
   date: 2025-12-25
diff --git a/_data/downloads.yml b/_data/downloads.yml
index 85a20e43ff..cf09cc3e3f 100644
--- a/_data/downloads.yml
+++ b/_data/downloads.yml
@@ -4,6 +4,7 @@
 # optional
 preview:
 
+  - 4.1.0-preview1
 
 stable:
 
diff --git a/_data/releases.yml b/_data/releases.yml
index 828cd438b1..cdd8e866a2 100644
--- a/_data/releases.yml
+++ b/_data/releases.yml
@@ -19,6 +19,37 @@
 # In order to get the release listed on the downloads page,
 # you also need to add an entry to `_data/downloads.yml'.
 
+# 4.1 series
+
+- version: 4.1.0-preview1
+  date: 2026-10-12
+  post: /en/news/2026/10/12/ruby-4-1-0-preview1-released/
+  tag: v4.1.0-preview1
+  stats:
+    files_changed: 6116
+    insertions: 311387
+    deletions: 219997
+  url:
+    gz:  https://cache.ruby-lang.org/pub/ruby/4.1/ruby-4.1.0-preview1.tar.gz
+    zip: https://cache.ruby-lang.org/pub/ruby/4.1/ruby-4.1.0-preview1.zip
+    xz:  https://cache.ruby-lang.org/pub/ruby/4.1/ruby-4.1.0-preview1.tar.xz
+  size:
+    gz:  26550186
+    zip: 32429495
+    xz:  20218640
+  sha1:
+    gz:  4f04a63c2e65945a4f4f7a6d1372783b60e68c5a
+    zip: 199cf5247f7fc55ff225b3fe6928a39a522000d0
+    xz:  3e6c6919bbdb178fd7d6210e3e960889094fac3c
+  sha256:
+    gz:  fb530bb88e90de3ae91c1310a27ae090e6bd989b8726de50ef12a890a85b88ef
+    zip: 2f1ea85203801c24e64ddf02fc2600f582a2544ef8c84d198111e56b0873b125
+    xz:  b81f20bf2bc72aa360785eb77ffa0c9f15343ac7316637fbf347500fc3e2e3a8
+  sha512:
+    gz:  f5628830685d0ce4ffb26294089c31c452e2e5a0bdcc6a5e0c670f335e52fb33eaaea7df3b834778db1fdde89cd2656d94743f6efa672c3bff6e89d64d5b7539
+    zip: fd32a7b544ec73f0e642202531170bf8fa4454b2c7ff069748b2bf8e530fc8ae4124572e570c4c56606cc90aeeb723d35cab152978b28ee36b4bb06c798529df
+    xz:  b58bc71a8734ceb38c9c301e0201ecd28559c97a3b93caa1d49e07ff34d51565b0b6ed98f05be41868cc09513784bd3e8b5340574fec37116a4ffcb218d396e4
+
 # 4.0 series
 
 - version: 4.0.7
diff --git a/en/news/_posts/2026-10-12-ruby-4-1-0-preview1-released.md b/en/news/_posts/2026-10-12-ruby-4-1-0-preview1-released.md
new file mode 100644
index 0000000000..db9c1d4e2d
--- /dev/null
+++ b/en/news/_posts/2026-10-12-ruby-4-1-0-preview1-released.md
@@ -0,0 +1,102 @@
+---
+layout: news_post
+title: "Ruby 4.1.0-preview1 Released"
+author: "naruse"
+translator:
+date: 2026-10-12 00:00:00 +0000
+lang: en
+---
+
+{% assign release = site.data.releases | where: "version", "4.1.0-preview1" | first %}
+We are pleased to announce the release of Ruby {{ release.version }}.
+Ruby 4.0 introduces "Ruby Box" and "ZJIT", and adds many improvements.
+
+## Ractor
+
+## Language changes
+
+* `super` in a module method that was called via `super` from a refinement
+  method now works correctly.
+  [[Feature #22309]]
+
+* `Module#clone` and `Module#dup` no longer rewrite the lexical scope of
+  copied methods. Constants and class variables resolve through the
+  original class, consistent with inheritance and mixins.
+  [[Feature #21981]]
+
+* `alias` and `Module#alias_method` in a module emit a deprecation warning
+  when the original method is not a method of the module or its ancestors
+  and is only found through the fallback to `Object`. The fallback will be
+  removed in Ruby 4.3, and such an alias will raise a `NameError`.
+  [[Bug #22276]]
+
+* `alias` and `Module#alias_method` emit a deprecation warning when the
+  original method is defined in a prepended module. This behavior will
+  be removed in Ruby 4.3, and alias lookup will start at the origin
+  class (after prepended modules).
+  [[Bug #22273]]
+
+## Stdlib updates
+
+
+
+### RubyGems and Bundler
+
+
+## Supported platforms
+
+
+
+## Compatibility issues
+
+  ```
+
+## Stdlib compatibility issues
+
+
+## C API updates
+
+
+## Implementation improvements
+
+
+
+## JIT
+
+
+
+See [NEWS](https://docs.ruby-lang.org/en/{{ release.tag }}/NEWS_md.html)
+or [commit logs](https://github.com/ruby/ruby/compare/v4_0_0...{{ release.tag }})
+for more details.
+
+With those changes, [{{ release.stats.files_changed }} files changed, {{ release.stats.insertions }} insertions(+), {{ release.stats.deletions }} deletions(-)](https://github.com/ruby/ruby/compare/v4_0_0...{{ release.tag }}#file_bucket)
+since Ruby 4.0.0!
+
+## Download
+
+* <{{ release.url.gz }}>
+
+      SIZE: {{ release.size.gz }}
+      SHA1: {{ release.sha1.gz }}
+      SHA256: {{ release.sha256.gz }}
+      SHA512: {{ release.sha512.gz }}
+
+* <{{ release.url.xz }}>
+
+      SIZE: {{ release.size.xz }}
+      SHA1: {{ release.sha1.xz }}
+      SHA256: {{ release.sha256.xz }}
+      SHA512: {{ release.sha512.xz }}
+
+* <{{ release.url.zip }}>
+
+      SIZE: {{ release.size.zip }}
+      SHA1: {{ release.sha1.zip }}
+      SHA256: {{ release.sha256.zip }}
+      SHA512: {{ release.sha512.zip }}
+
+## What is Ruby
+
+Ruby was first developed by Matz (Yukihiro Matsumoto) in 1993,
+and is now developed as Open Source. It runs on multiple platforms
+and is used all over the world especially for web development.