diff --git a/assets/highlighting-tests/ruby.rb b/assets/highlighting-tests/ruby.rb
new file mode 100644
index 00000000000..69b1c682316
--- /dev/null
+++ b/assets/highlighting-tests/ruby.rb
@@ -0,0 +1,102 @@
+# Comments
+# Single-line comment
+
+=begin
+Multi-line
+comment
+=end
+
+# Numbers
+42
+3.14
+0.5
+1e10
+1.5e-3
+0xff
+0xFF
+0b1010
+0o77
+1_000_000
+3.14r
+2i
+
+# Constants
+true
+false
+nil
+Object
+String
+
+# Strings
+'single quotes with escape: \' \n \t \\'
+"double quotes with escape: \" \n \t \\"
+`echo shell command`
+
+# Symbols and variables
+:symbol
+:method_name?
+@instance_var
+@@class_var
+$global_var
+
+# Control flow keywords
+if true
+  puts "yes"
+elsif false
+  puts "no"
+else
+  puts "maybe"
+end
+
+unless nil
+  puts "not nil"
+end
+
+case 42
+when 1
+  puts "one"
+else
+  puts "other"
+end
+
+for i in 1..3
+  next if i == 2
+  break if i == 3
+end
+
+while false
+  redo
+end
+
+begin
+  raise "oops"
+rescue StandardError => e
+  retry
+ensure
+  puts e
+end
+
+# Definitions and method calls
+module Demo
+  class Animal
+    def initialize(name)
+      @name = name
+    end
+
+    def speak! =  puts "#{@name} speaks"
+  end
+end
+
+alias old_speak speak!
+undef old_speak
+
+BEGIN { puts "start" }
+END { puts "finish" }
+defined? Demo
+self
+super
+yield
+
+puts "hello"
+Array.new(3)
+greet("world")
diff --git a/crates/lsh/definitions/ruby.lsh b/crates/lsh/definitions/ruby.lsh
new file mode 100644
index 00000000000..0e7079cd12d
--- /dev/null
+++ b/crates/lsh/definitions/ruby.lsh
@@ -0,0 +1,100 @@
+#[display_name = "Ruby"]
+#[path = "**/*.rb"]
+#[path = "**/*.rake"]
+#[path = "**/*.ru"]
+#[path = "**/Gemfile"]
+#[path = "**/Rakefile"]
+pub fn ruby() {
+    var zero = 0;
+    until /$/ {
+        yield other;
+
+        if off == zero {
+            if /=begin\>/ {
+                loop {
+                    yield comment;
+                    await input;
+                    if off == zero {
+                        if /=end\>/ {
+                            yield comment;
+                            break;
+                        }
+                    }
+                }
+                continue;
+            }
+        }
+
+        if /#.*/ {
+            yield comment;
+        } else if /'/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /'/ { yield string; break; }
+                await input;
+            }
+        } else if /"/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /"/ { yield string; break; }
+                await input;
+            }
+        } else if /`/ {
+            loop {
+                yield string;
+                if /\\./ {}
+                else if /`/ { yield string; break; }
+                await input;
+            }
+        } else if /(?:begin|break|case|class|do|else|elsif|end|ensure|for|if|in|module|next|redo|rescue|retry|return|then|unless|until|when|while)\>/ {
+            yield keyword.control;
+        } else if /def\s+(\w+[!?=]?)/ {
+            yield keyword.control;
+            yield $1 as method;
+        } else if /(?:BEGIN|END|alias|defined\?|self|super|undef|yield)\>/ {
+            yield keyword.other;
+        } else if /(?:true|false|nil)\>/ {
+            yield constant.language;
+        } else if /\.\.\.?/ {
+            // Range operator.
+        } else if /(?i:-?(?:0x[\da-fA-F_]+|0b[01_]+|0o[0-7_]+)r?i?)/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(?i:-?[\d_]+\.[\d_]+(?:e[+-]?[\d_]+)?r?i?)/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(?i:-?\.[\d_]+(?:e[+-]?[\d_]+)?r?i?)/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(?i:-?[\d_]+(?:e[+-]?[\d_]+)?r?i?)/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(?:@{1,2}|\$)[A-Za-z_]\w*/ {
+            yield variable;
+        } else if /:[A-Za-z_]\w*[!?=]?/ {
+            yield constant.language;
+        } else if /[A-Z]\w*/ {
+            yield constant.language;
+        } else if /(\w+[!?=]?)\s*\(/ {
+            yield $1 as method;
+        } else if /\w+[!?=]?/ {
+            // Gobble word chars to align the next iteration on a word boundary.
+        }
+
+        yield other;
+    }
+}