diff --git a/assets/highlighting-tests/toml.toml b/assets/highlighting-tests/toml.toml
new file mode 100644
index 00000000000..c46dd49b535
--- /dev/null
+++ b/assets/highlighting-tests/toml.toml
@@ -0,0 +1,45 @@
+title = "TOML Example"          # inline comment
+enabled = true
+disabled = false
+
+[owner]
+name = "Tom Preston-Werner"
+"quoted key" = "value"
+dob = 1979-05-27T07:32:00-08:00
+bare-key = 'literal string'
+winpath = 'C:\Users\me\'
+dotted.nested.key = 42
+
+[database]
+ports = [8000, 8001, 8002]
+data = [["delta", "phi"], [3.14]]
+temp_targets = { cpu = 79.5, case = 72.0 }
+hex = 0xDEAD_BEEF
+octal = 0o755
+binary = 0b1101_0010
+negative = -17
+positive = +99
+scientific = 6.626e-34
+infinity = inf
+plus_infinity = +inf
+not_a_number = -nan
+
+[servers.alpha]
+ip = "10.0.0.1"
+local_date = 1979-05-27
+local_time = 07:32:00.999999
+
+multiline = """
+a multi-line basic string \
+with an escape and a "quote" inside
+"""
+
+regex = '''\d{4}-\d{2}-\d{2}'''
+
+[[products]]
+name = "Hammer"
+sku = 777777777
+
+[[products]]
+name = "Nail"
+color = "gray"
diff --git a/crates/lsh/definitions/toml.lsh b/crates/lsh/definitions/toml.lsh
new file mode 100644
index 00000000000..ba21c13766e
--- /dev/null
+++ b/crates/lsh/definitions/toml.lsh
@@ -0,0 +1,89 @@
+#[display_name = "TOML"]
+#[path = "**/*.toml"]
+#[path = "**/Cargo.lock"]
+pub fn toml() {
+    yield other;
+
+    // Optional leading whitespace.
+    if /[ \t]+/ {
+        yield other;
+    }
+
+    // Table headers: [table], [a.b.c] and [[array.of.tables]].
+    if /\[\[[^\]]*\]\]/ {
+        yield meta.header;
+    } else if /\[[^\]]*\]/ {
+        yield meta.header;
+    }
+
+    yield other;
+
+    until /$/ {
+        yield other;
+
+        if /#.*/ {
+            yield comment;
+        } else if /"""/ {
+            // Multi-line basic string.
+            loop {
+                yield string;
+                if /\\./ {
+                } else if /"""/ {
+                    yield string;
+                    break;
+                }
+                await input;
+            }
+        } else if /'''/ {
+            // Multi-line literal string (no escapes).
+            loop {
+                yield string;
+                if /'''/ {
+                    yield string;
+                    break;
+                }
+                await input;
+            }
+        }
+        // Quoted key: "key" = ... or 'key' = ... (also matches inside inline tables).
+        else if /("[^"]*"|'[^']*')[ \t]*=/ {
+            yield $1 as variable;
+        }
+        // Bare or dotted key: key = ..., a.b.c = ... (also matches inside inline tables).
+        else if /([A-Za-z0-9_.-]+)[ \t]*=/ {
+            yield $1 as variable;
+        } else if /"/ {
+            double_quote_string();
+        } else if /'/ {
+            // Literal string: no escape sequences, so a trailing backslash
+            // (e.g. a Windows path like 'C:\dir\') still ends the string.
+            until /$/ {
+                yield string;
+                if /'/ {
+                    yield string;
+                    break;
+                }
+            }
+        } else if /(?:true|false)\>/ {
+            yield constant.language;
+        } else if /\+?-?(?:inf|nan)\>/ {
+            yield constant.language;
+        } else if /\d{4}-\d{2}-\d{2}(?:[Tt ]\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:[Zz]|[+-]\d{2}:\d{2})?)?/ {
+            // Offset date-time, local date-time and local date.
+            yield constant.numeric;
+        } else if /\d{2}:\d{2}:\d{2}(?:\.\d+)?/ {
+            // Local time.
+            yield constant.numeric;
+        } else if /\+?-?(?:0x[0-9a-fA-F][0-9a-fA-F_]*|0o[0-7][0-7_]*|0b[01][01_]*|\d[\d_]*(?:\.\d[\d_]*)?(?:[eE][+-]?\d[\d_]*)?)/ {
+            if /\w+/ {
+                // Not a number after all.
+            } else {
+                yield constant.numeric;
+            }
+        } else if /\w+/ {
+            // Gobble word chars to align the next iteration on a word boundary.
+        }
+
+        yield other;
+    }
+}