diff --git a/completions/internal_commands_list.txt b/completions/internal_commands_list.txt
index 9a87e645062e1..45d6e2f367d90 100644
--- a/completions/internal_commands_list.txt
+++ b/completions/internal_commands_list.txt
@@ -86,6 +86,7 @@ rm
 rubocop
 ruby
 search
+setup-ruby
 sh
 shellenv
 style
diff --git a/completions/zsh/_brew b/completions/zsh/_brew
index d853a5fffa9b6..334445c60bad9 100644
--- a/completions/zsh/_brew
+++ b/completions/zsh/_brew
@@ -205,6 +205,7 @@ __brew_internal_commands() {
     'rubocop:Installs, configures and runs Homebrew'\''s `rubocop`'
     'ruby:Run a Ruby instance with Homebrew'\''s libraries loaded'
     'search:Perform a substring search of cask tokens and formula names for text'
+    'setup-ruby:Installs and configures Homebrew'\''s Ruby'
     'sh:Enter an interactive shell for Homebrew'\''s build environment'
     'shellenv:Print export statements'
     'style:Check formulae or files for conformance to Homebrew style guidelines'
diff --git a/docs/Manpage.md b/docs/Manpage.md
index c9d3c95d9b325..ccbb49305d4fb 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -663,6 +663,10 @@ is flanked by slashes, it is interpreted as a regular expression.
 * `--ubuntu`:
   Search for *`text`* in the given database.
 
+### `setup-ruby`
+
+Installs and configures Homebrew's Ruby.
+
 ### `shellenv [bash|csh|fish|pwsh|sh|tcsh|zsh]`
 
 Print export statements. When run in a shell, this installation of Homebrew will be added to your `PATH`, `MANPATH`, and `INFOPATH`.
diff --git a/manpages/brew.1 b/manpages/brew.1
index 091a347691bec..7a993ca6256b3 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -944,6 +944,9 @@ Search for \fItext\fR in the given database\.
 \fB\-\-ubuntu\fR
 Search for \fItext\fR in the given database\.
 .
+.SS "\fBsetup\-ruby\fR"
+Installs and configures Homebrew\'s Ruby\.
+.
 .SS "\fBshellenv [bash|csh|fish|pwsh|sh|tcsh|zsh]\fR"
 Print export statements\. When run in a shell, this installation of Homebrew will be added to your \fBPATH\fR, \fBMANPATH\fR, and \fBINFOPATH\fR\.
 .