diff --git a/ace-modes.d.ts b/ace-modes.d.ts
index 20a0c61c512..e1a88ebc78c 100644
--- a/ace-modes.d.ts
+++ b/ace-modes.d.ts
@@ -340,6 +340,12 @@ declare module "ace-code/src/mode/erlang" {
 declare module "ace-code/src/mode/erlang_highlight_rules" {
   export const ErlangHighlightRules: new () => import(".").Ace.HighlightRules;
 }
+declare module "ace-code/src/mode/flix" {
+  export const Mode: new () => import(".").Ace.SyntaxMode;
+}
+declare module "ace-code/src/mode/flix_highlight_rules" {
+  export const FlixHighlightRules: new () => import(".").Ace.HighlightRules;
+}
 declare module "ace-code/src/mode/forth" {
   export const Mode: new () => import(".").Ace.SyntaxMode;
 }
diff --git a/demo/kitchen-sink/docs/flix.flix b/demo/kitchen-sink/docs/flix.flix
new file mode 100644
index 00000000000..653f94cf9dd
--- /dev/null
+++ b/demo/kitchen-sink/docs/flix.flix
@@ -0,0 +1,35 @@
+/// Mooo's `n` times on channel `c`.
+def mooo(tx: Sender[String, r], n: Int32): Unit \ IO =
+    match n {
+        case 0 => ()
+        case x => Channel.send("Mooo!", tx); mooo(tx, x - 1)
+    }
+
+/// Meow's `n` times on channel `c`.
+def meow(tx: Sender[String, r], n: Int32): Unit \ IO =
+    match n {
+        case 0 => ()
+        case x => Channel.send("Meow!", tx); meow(tx, x - 1)
+    }
+
+/// Hiss'es `n` times on channel `c`.
+def hiss(tx: Sender[String, r], n: Int32): Unit \ IO =
+    match n {
+        case 0 => ()
+        case x => Channel.send("Hiss!", tx); hiss(tx, x - 1)
+    }
+
+/// Start the animal farm...
+def main(): Unit \ IO = region rc {
+    let (tx1, rx1) = Channel.buffered(rc, 10);
+    let (tx2, rx2) = Channel.buffered(rc, 10);
+    let (tx3, rx3) = Channel.buffered(rc, 10);
+    spawn mooo(tx1, 0) @ rc;
+    spawn meow(tx2, 3) @ rc;
+    spawn hiss(tx3, 7) @ rc;
+    select {
+        case m <- recv(rx1) => m |> println
+        case m <- recv(rx2) => m |> println
+        case m <- recv(rx3) => m |> println
+    }
+}
diff --git a/src/ext/modelist.js b/src/ext/modelist.js
index b114c1e7975..6678f1e03b2 100644
--- a/src/ext/modelist.js
+++ b/src/ext/modelist.js
@@ -88,6 +88,7 @@ var supportedModes = {
     Elixir:      ["ex|exs"],
     Elm:         ["elm"],
     Erlang:      ["erl|hrl"],
+    Flix:        ["flix"],
     Forth:       ["frt|fs|ldr|fth|4th"],
     Fortran:     ["f|f90"],
     FSharp:      ["fsi|fs|ml|mli|fsx|fsscript"],
diff --git a/src/mode/_test/tokens_flix.json b/src/mode/_test/tokens_flix.json
new file mode 100644
index 00000000000..2182c6d9a98
--- /dev/null
+++ b/src/mode/_test/tokens_flix.json
@@ -0,0 +1,293 @@
+[[
+    "start",
+    ["text", "    "]
+],[
+    "start",
+    ["comment.block", "/* Hello comment */"],
+    ["text", "\n"],
+    ["comment.block", "/* Hello \n comment */"],
+    ["text", "\n"],
+    ["comment.line", "// Hello comment"]
+],[
+    "start",
+    ["keyword", "use"],
+    ["text", " "],
+    ["identifier", "Add"],
+    ["text", "."],
+    ["identifier", "add"]
+],[
+    "start",
+    ["storage.type", "mod"],
+    ["text", " "],
+    ["paren.lparen", "{"],
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Int32"],
+    ["text", " = "],
+    ["constant.numeric", "42"],
+    ["paren.rparen", "}"]
+],[
+    "start",
+    ["storage.type", "class"],
+    ["text", " "],
+    ["identifier", "Add"],
+    ["paren.lparen", "["],
+    ["identifier", "a"],
+    ["paren.rparen", "]"],
+    ["text", " "],
+    ["paren.lparen", "{"],
+    ["paren.rparen", "}"]
+],[
+    "start",
+    ["storage.type", "enum"],
+    ["text", " "],
+    ["identifier", "Down"],
+    ["paren.lparen", "["],
+    ["identifier", "a"],
+    ["paren.rparen", "]"],
+    ["text", " "],
+    ["storage.modifier", "with"],
+    ["text", " "],
+    ["identifier", "Sendable"],
+    ["text", " "],
+    ["paren.lparen", "{"],
+    ["storage.type", "case"],
+    ["text", " "],
+    ["identifier", "Down"],
+    ["paren.lparen", "("],
+    ["identifier", "a"],
+    ["paren.rparen", ")}"]
+],[
+    "start",
+    ["storage.type", "eff"],
+    ["text", " "],
+    ["identifier", "NonDet"]
+],[
+    "start",
+    ["storage.type", "type"],
+    ["text", " "],
+    ["storage.type", "alias"],
+    ["text", " "],
+    ["identifier", "Static"],
+    ["text", " = "],
+    ["identifier", "Impure"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Int32"],
+    ["text", " = "],
+    ["paren.lparen", "{"],
+    ["constant.numeric", "42"],
+    ["paren.rparen", "}"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Float64"],
+    ["text", " = "],
+    ["keyword.control", "if"],
+    ["paren.lparen", "("],
+    ["constant.language.boolean", "true"],
+    ["paren.rparen", ")"],
+    ["paren.lparen", "{"],
+    ["constant.numeric", "42.0"],
+    ["paren.rparen", "}"],
+    ["keyword.control", "else"],
+    ["paren.lparen", "{"],
+    ["constant.numeric", "43.0"],
+    ["paren.rparen", "}"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "String"],
+    ["text", " = "],
+    ["string", "\"Hello"],
+    ["constant.character.escape", "\\\""],
+    ["string", "World"],
+    ["constant.character.escape", "\\u0021"],
+    ["string", "\""]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Char"],
+    ["text", " = "],
+    ["constant.character", "'a'"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Char"],
+    ["text", " = "],
+    ["constant.character", "'"],
+    ["constant.character.escape", "\\u0021"],
+    ["constant.character", "'"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Char"],
+    ["text", " = "],
+    ["constant.character", "'"],
+    ["constant.character.escape", "\\'"],
+    ["constant.character", "'"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["identifier", "Regex"],
+    ["text", " = "],
+    ["string.regexp", "regex\"Hello"],
+    ["constant.character.escape", "\\\""],
+    ["string.regexp", "World"],
+    ["constant.character.escape", "\\u0021"],
+    ["string.regexp", "\""]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "String"],
+    ["text", " = "],
+    ["keyword", "???"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "String"],
+    ["text", " = "],
+    ["keyword", "?someHole"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Int32"],
+    ["text", " = "],
+    ["constant.numeric", "0x123i32"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Int32"],
+    ["text", " = "],
+    ["constant.numeric", "42i32"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Float64"],
+    ["text", " = "],
+    ["constant.numeric", "42.0f64"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Bool"],
+    ["text", " = "],
+    ["constant.language.boolean", "true"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Bool"],
+    ["text", " = "],
+    ["constant.language.boolean", "false"]
+],[
+    "start",
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["identifier", "Null"],
+    ["text", " = "],
+    ["constant.language", "null"]
+],[
+    "start",
+    ["storage.modifier", "@Lazy"],
+    ["text", "\n"],
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Int32"],
+    ["text", " = "],
+    ["constant.numeric", "42"]
+],[
+    "start",
+    ["storage.modifier", "pub"],
+    ["text", " "],
+    ["storage.type", "def"],
+    ["text", " "],
+    ["identifier", "main"],
+    ["paren.lparen", "("],
+    ["paren.rparen", ")"],
+    ["text", ": "],
+    ["support.type", "Int32"],
+    ["text", " = "],
+    ["constant.numeric", "42"]
+]]
\ No newline at end of file
diff --git a/src/mode/flix.js b/src/mode/flix.js
new file mode 100644
index 00000000000..ac4c9630239
--- /dev/null
+++ b/src/mode/flix.js
@@ -0,0 +1,16 @@
+"use strict";
+
+var oop = require("../lib/oop");
+var TextMode = require("./text").Mode;
+var FlixHighlightRules = require("./flix_highlight_rules").FlixHighlightRules;
+
+var Mode = function() {
+    this.HighlightRules = FlixHighlightRules;
+};
+oop.inherits(Mode, TextMode);
+
+(function() {
+    this.$id = "ace/mode/flix";
+}).call(Mode.prototype);
+
+exports.Mode = Mode;
\ No newline at end of file
diff --git a/src/mode/flix_highlight_rules.js b/src/mode/flix_highlight_rules.js
new file mode 100644
index 00000000000..a5a67ce69b4
--- /dev/null
+++ b/src/mode/flix_highlight_rules.js
@@ -0,0 +1,152 @@
+"use strict";
+
+var oop = require("../lib/oop");
+var TextHighlightRules = require("./text_highlight_rules").TextHighlightRules;
+
+var FlixHighlightRules = function() {
+    
+    var keywords = (
+        "use|checked_cast|checked_ecast|unchecked_cast|masked_cast|as|discard|from|" +
+        "into|inject|project|solve|query|where|select|force|import|region|red|deref"
+    );
+    var controlKeywords = (
+        "choose|debug|do|for|forA|forM|foreach|yield|if|else|case|" +
+        "match|typematch|try|catch|resume|spawn|par|branch|jumpto"
+    );
+    var operators = "not|and|or|fix";
+    var declarations = "eff|def|law|enum|case|type|alias|class|instance|mod|let";
+    var modifiers = "with|without|opaque|lazy|lawful|pub|override|sealed|static";
+    var primitives = "Unit|Bool|Char|Float32|Float64|Int8|Int16|Int32|Int64|BigInt|String";
+
+    var keywordMapper = this.createKeywordMapper({
+        "keyword": keywords,
+        "keyword.control": controlKeywords,
+        "keyword.operator": operators,
+        "storage.type": declarations,
+        "storage.modifier": modifiers,
+        "support.type": primitives
+    }, "identifier");
+
+    this.$rules = {
+        "start" : [
+            {
+                token : "comment.line",
+                regex : "\\/\\/.*$"
+            }, {
+                token : "comment.block",
+                regex : "\\/\\*",
+                next : "comment"
+            }, {
+                token : "string",
+                regex : '"',
+                next : "string"
+            }, {
+                token : "string.regexp",
+                regex : 'regex"',
+                next : "regex"
+            }, {
+                token : "constant.character",
+                regex : "'",
+                next : "char"
+            }, {
+                token : "constant.numeric", // hex
+                regex : "0x[a-fA-F0-9](_*[a-fA-F0-9])*(i8|i16|i32|i64|ii)?\\b"
+            }, {
+                token : "constant.numeric", // float
+                regex : "[0-9](_*[0-9])*\\.[0-9](_*[0-9])*(f32|f64)?\\b"
+            }, {
+                token : "constant.numeric", // integer
+                regex : "[0-9](_*[0-9])*(i8|i16|i32|i64|ii)?\\b"
+            }, {
+                token : "constant.language.boolean",
+                regex : "(true|false)\\b"
+            }, {
+                token : "constant.language",
+                regex : "null\\b"
+            }, {
+                token : "keyword.operator",
+                regex : "\\->|~>|<\\-|=>"
+            }, {
+                token : "storage.modifier",
+                regex : "@(Deprecated|Experimental|Internal|ParallelWhenPure|Parallel|LazyWhenPure|Lazy|Skip|Test)\\b"
+            }, {
+                token : "keyword", // hole
+                regex : "(\\?\\?\\?|\\?[a-zA-Z0-9]+)"
+            }, {
+                token : keywordMapper,
+                regex : "[a-zA-Z_$][a-zA-Z0-9_$]*\\b"
+            }, {
+                token : "paren.lparen",
+                regex : "[[({]"
+            }, {
+                token : "paren.rparen",
+                regex : "[\\])}]"
+            }, {
+                token : "text",
+                regex : "\\s+"
+            }
+        ],
+        "comment" : [
+            {
+                token : "comment.block",
+                regex : "\\*\\/",
+                next : "start"
+            }, {
+                defaultToken : "comment.block"
+            }
+        ],
+        "string" : [
+            {
+                token : "constant.character.escape", // unicode
+                regex : "\\\\(u[0-9a-fA-F]{4})"
+            }, {
+                token : "constant.character.escape",
+                regex : '\\\\.'
+            }, {
+                token : "string",
+                regex : '"',
+                next : "start"
+            }, {
+                token : "string",
+                regex : '[^"\\\\]+'
+            }
+        ],
+        "regex" : [
+            {
+                token : "constant.character.escape", // unicode
+                regex : "\\\\(u[0-9a-fA-F]{4})"
+            }, {
+                token : "constant.character.escape",
+                regex : '\\\\.'
+            }, {
+                token : "string.regexp",
+                regex : '"',
+                next : "start"
+            }, {
+                token : "string.regexp",
+                regex : '[^"\\\\]+'
+            }
+        ],
+        "char" : [
+            {
+                token : "constant.character.escape", // unicode
+                regex : "\\\\(u[0-9a-fA-F]{4})"
+            }, {
+                token : "constant.character.escape",
+                regex : '\\\\.'
+            }, {
+                token : "constant.character",
+                regex : "'",
+                next : "start"
+            }, {
+                token : "constant.character",
+                regex : "[^'\\\\]+"
+            }
+        ]
+    };
+
+};
+
+oop.inherits(FlixHighlightRules, TextHighlightRules);
+
+exports.FlixHighlightRules = FlixHighlightRules;
\ No newline at end of file