diff --git a/scripts/bundle.js b/scripts/bundle.js
index b1ad53af..531a17c2 100644
--- a/scripts/bundle.js
+++ b/scripts/bundle.js
@@ -49,6 +49,7 @@ bundleOne('ruby/ruby');
 bundleOne('rust/rust');
 bundleOne('scss/scss');
 bundleOne('sql/sql');
+bundleOne('st/st');
 bundleOne('swift/swift');
 bundleOne('vb/vb');
 bundleOne('xml/xml');
diff --git a/src/monaco.contribution.ts b/src/monaco.contribution.ts
index d1c71f9c..340dddd3 100644
--- a/src/monaco.contribution.ts
+++ b/src/monaco.contribution.ts
@@ -39,6 +39,7 @@ import './sb/sb.contribution';
 import './scss/scss.contribution';
 import './solidity/solidity.contribution';
 import './sql/sql.contribution';
+import './st/st.contribution';
 import './swift/swift.contribution';
 import './vb/vb.contribution';
 import './xml/xml.contribution';
diff --git a/src/st/st.contribution.ts b/src/st/st.contribution.ts
new file mode 100644
index 00000000..a30c2dc6
--- /dev/null
+++ b/src/st/st.contribution.ts
@@ -0,0 +1,17 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+'use strict';
+
+import { registerLanguage } from '../_.contribution';
+
+// Allow for running under nodejs/requirejs in tests
+const _monaco: typeof monaco = (typeof monaco === 'undefined' ? (<any>self).monaco : monaco);
+
+registerLanguage({
+	id: 'st',
+	extensions: ['.st'],
+	aliases: ['StructuredText', 'scl', 'stl'],
+	loader: () => _monaco.Promise.wrap(import('./st'))
+});
diff --git a/src/st/st.test.ts b/src/st/st.test.ts
new file mode 100644
index 00000000..cc8f8eba
--- /dev/null
+++ b/src/st/st.test.ts
@@ -0,0 +1,133 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import { testTokenization } from '../test/testRunner';
+testTokenization('st', [
+	[{
+		line: "xVar : BOOL;",
+		tokens: [
+			{ startIndex: 0, type: 'identifier.st' },
+			{ startIndex: 4, type: 'white.st' },
+			{ startIndex: 5, type: '' },
+			{ startIndex: 6, type: 'white.st' },
+			{ startIndex: 7, type: 'type.st' },
+			{ startIndex: 11, type: 'delimiter.st' },
+		]
+	}],
+	[{
+		line: "xStart AT %IX0.0.1: BOOL := TRUE;",
+		tokens: [
+			{ startIndex: 0, type: 'identifier.st' },
+			{ startIndex: 6, type: 'white.st' },
+			{ startIndex: 7, type: 'keyword.st' },
+			{ startIndex: 9, type: 'white.st' },
+			{ startIndex: 10, type: 'tag.st' },
+			{ startIndex: 18, type: '' },
+			{ startIndex: 19, type: 'white.st' },
+			{ startIndex: 20, type: 'type.st' },
+			{ startIndex: 24, type: 'white.st' },
+			{ startIndex: 25, type: '' },
+			{ startIndex: 27, type: 'white.st' },
+			{ startIndex: 28, type: 'constant.st' },
+			{ startIndex: 32, type: 'delimiter.st' },
+		]
+	}],
+	[{
+		line: "IF a > 2#0000_0110 THEN (* Somethign ' happens *)",
+		tokens: [
+			{ startIndex: 0, type: 'keyword.st' },
+			{ startIndex: 2, type: 'white.st' },
+			{ startIndex: 3, type: 'identifier.st' },
+			{ startIndex: 4, type: 'white.st' },
+			{ startIndex: 5, type: '' },
+			{ startIndex: 6, type: 'white.st' },
+			{ startIndex: 7, type: 'number.binary.st' },
+			{ startIndex: 18, type: 'white.st' },
+			{ startIndex: 19, type: 'keyword.st' },
+			{ startIndex: 23, type: 'white.st' },
+			{ startIndex: 24, type: 'comment.st' },
+		]
+	}],
+	[{
+		line: "TON1(IN := TRUE, PT := T#20ms, Q => xStart); // Run timer",
+		tokens: [
+			{ startIndex: 0, type: 'identifier.st' },
+			{ startIndex: 4, type: 'delimiter.parenthesis.st' },
+			{ startIndex: 5, type: 'identifier.st' },
+			{ startIndex: 7, type: 'white.st' },
+			{ startIndex: 8, type: '' },
+			{ startIndex: 10, type: 'white.st' },
+			{ startIndex: 11, type: 'constant.st' },
+			{ startIndex: 15, type: '' },
+			{ startIndex: 16, type: 'white.st' },
+			{ startIndex: 17, type: 'identifier.st' },
+			{ startIndex: 19, type: 'white.st' },
+			{ startIndex: 20, type: '' },
+			{ startIndex: 22, type: 'white.st' },
+			{ startIndex: 23, type: 'tag.st' },
+			{ startIndex: 29, type: '' },
+			{ startIndex: 30, type: 'white.st' },
+			{ startIndex: 31, type: 'identifier.st' },
+			{ startIndex: 32, type: 'white.st' },
+			{ startIndex: 33, type: '' },
+			{ startIndex: 35, type: 'white.st' },
+			{ startIndex: 36, type: 'identifier.st' },
+			{ startIndex: 42, type: 'delimiter.parenthesis.st' },
+			{ startIndex: 43, type: 'delimiter.st' },
+			{ startIndex: 44, type: 'white.st' },
+			{ startIndex: 45, type: 'comment.st' },
+		]
+	}],
+	// Numbers
+	[{
+		line: '0',
+		tokens: [
+			{ startIndex: 0, type: 'number.st' }
+		]
+	}],
+
+	[{
+		line: '0.0',
+		tokens: [
+			{ startIndex: 0, type: 'number.float.st' }
+		]
+	}],
+
+	[{
+		line: '2#000_0101',
+		tokens: [
+			{ startIndex: 0, type: 'number.binary.st' }
+		]
+	}],
+	[{
+		line: '16#0f',
+		tokens: [
+			{ startIndex: 0, type: 'number.hex.st' }
+		]
+	}],
+
+	[{
+		line: '23.5',
+		tokens: [
+			{ startIndex: 0, type: 'number.float.st' }
+		]
+	}],
+
+	[{
+		line: '23.5e3',
+		tokens: [
+			{ startIndex: 0, type: 'number.float.st' }
+		]
+	}],
+
+	[{
+		line: '23.5E3',
+		tokens: [
+			{ startIndex: 0, type: 'number.float.st' }
+		]
+	}],
+]);
diff --git a/src/st/st.ts b/src/st/st.ts
new file mode 100644
index 00000000..3a822f98
--- /dev/null
+++ b/src/st/st.ts
@@ -0,0 +1,178 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import IRichLanguageConfiguration = monaco.languages.LanguageConfiguration;
+import ILanguage = monaco.languages.IMonarchLanguage;
+
+export const conf: IRichLanguageConfiguration = {
+	comments: {
+		lineComment: '//',
+		blockComment: ['(*', '*)'],
+	},
+	brackets: [
+		['{', '}'],
+		['[', ']'],
+		['(', ')']
+	],
+	autoClosingPairs: [
+		{ open: '[', close: ']' },
+		{ open: '{', close: '}' },
+		{ open: '(', close: ')' },
+		{ open: '/*', close: '*/' },
+		{ open: '\'', close: '\'', notIn: ['string_sq'] },
+		{ open: '"', close: '"', notIn: ['string_dq'] },
+	],
+	surroundingPairs: [
+		{ open: '{', close: '}' },
+		{ open: '[', close: ']' },
+		{ open: '(', close: ')' },
+		{ open: '"', close: '"' },
+		{ open: '\'', close: '\'' },
+	],
+	folding: {
+		markers: {
+			start: new RegExp("^\\s*#pragma\\s+region\\b"),
+			end: new RegExp("^\\s*#pragma\\s+endregion\\b")
+		}
+	}
+};
+
+export const language = <ILanguage>{
+	defaultToken: '',
+	tokenPostfix: '.st',
+	ignoreCase: true,
+
+	brackets: [
+		{ token: 'delimiter.curly', open: '{', close: '}' },
+		{ token: 'delimiter.parenthesis', open: '(', close: ')' },
+		{ token: 'delimiter.square', open: '[', close: ']' }
+	],
+
+	keywords: ['if', 'end_if', 'elsif', 'else', 'case', 'of', 'to',
+		'do', 'with', 'by', 'while', 'repeat', 'end_while', 'end_repeat', 'end_case',
+		'for', 'end_for', 'task', 'retain', 'non_retain', 'constant', 'with', 'at',
+		'exit', 'return', 'interval', 'priority', 'address', 'port', 'on_channel',
+		'then', 'iec', 'file', 'uses', 'version', 'packagetype', 'displayname',
+		'copyright', 'summary', 'vendor', 'common_source', 'from'],
+
+	constant: ['false', 'true', 'null'],
+
+	defineKeywords: [
+		'var', 'var_input', 'var_output', 'var_in_out', 'var_temp', 'var_global',
+		'var_access', 'var_external', 'end_var',
+
+		'type', 'end_type', 'struct', 'end_struct', 'program', 'end_program',
+		'function', 'end_function', 'function_block', 'end_function_block',
+
+		'configuration', 'end_configuration', 'tcp', 'end_tcp', 'recource',
+		'end_recource', 'channel', 'end_channel', 'library', 'end_library',
+		'folder', 'end_folder', 'binaries', 'end_binaries', 'includes',
+		'end_includes', 'sources', 'end_sources',
+
+		'action', 'end_action', 'step', 'initial_step', 'end_step', 'transaction', 'end_transaction'
+	],
+
+	typeKeywords: ['int', 'sint', 'dint', 'lint', 'usint', 'uint', 'udint', 'ulint',
+		'real', 'lreal', 'time', 'date', 'time_of_day', 'date_and_time', 'string',
+		'bool', 'byte', 'world', 'dworld', 'array', 'pointer', 'lworld'],
+
+	operators: ['=', '>', '<', ':', ':=', '<=', '>=', '<>', '&', '+', '-', '*', '**',
+		'MOD', '^', 'or', 'and', 'not', 'xor', 'abs', 'acos', 'asin', 'atan', 'cos',
+		'exp', 'expt', 'ln', 'log', 'sin', 'sqrt', 'tan', 'sel', 'max', 'min', 'limit',
+		'mux', 'shl', 'shr', 'rol', 'ror', 'indexof', 'sizeof', 'adr', 'adrinst',
+		'bitadr', 'is_valid'],
+
+	builtinVariables: [
+
+	],
+
+	builtinFunctions: ['sr', 'rs', 'tp', 'ton', 'tof', 'eq', 'ge', 'le', 'lt',
+		'ne', 'round', 'trunc', 'ctd', 'сtu', 'ctud', 'r_trig', 'f_trig',
+		'move', 'concat', 'delete', 'find', 'insert', 'left', 'len', 'replace',
+		'right', 'rtc'],
+
+	// we include these common regular expressions
+	symbols: /[=><!~?:&|+\-*\/\^%]+/,
+
+	// C# style strings
+	escapes: /\\(?:[abfnrtv\\"']|x[0-9A-Fa-f]{1,4}|u[0-9A-Fa-f]{4}|U[0-9A-Fa-f]{8})/,
+
+	// The main tokenizer for our languages
+	tokenizer: {
+		root: [
+			[/(T|DT|TOD)#[0-9:-_shmyd]*/, 'tag'],
+			[/[A-Za-z]{1,6}#[0-9]*/, 'tag'],
+			[/\%(I|Q|M)(X|B|W|D|L)[0-9\.]*/, 'tag'],
+			[/\%(I|Q|M)[0-9\.]*/, 'tag'],
+			[/(TO_|CTU_|CTD_|CTUD_|MUX_|SEL_)[A_Za-z]*/, 'predefined'],
+			[/[A_Za-z]*(_TO_)[A_Za-z]*/, 'predefined'],
+
+			// identifiers and keywords
+			[/[a-zA-Z_]\w*/, {
+				cases: {
+					'@operators': 'operators',
+					'@keywords': 'keyword',
+					'@typeKeywords': 'type',
+					'@defineKeywords': 'variable',
+					'@constant': 'constant',
+					'@builtinVariables': 'predefined',
+					'@builtinFunctions': 'predefined',
+					'@default': 'identifier'
+				}
+			}],
+
+			{ include: '@whitespace' },
+
+			[/[;.]/, 'delimiter'],
+			[/[{}()\[\]]/, '@brackets'],
+			[/\d*\.\d+([eE][\-+]?\d+)?/, 'number.float'],
+			[/16#[0-9a-fA-F]+/, 'number.hex'],
+			[/2#[0-9_]+/, 'number.binary'],
+			[/\d+/, 'number'],
+
+
+
+			[/"([^"\\]|\\.)*$/, 'string.invalid'],  // non-teminated string
+			[/"/, { token: 'string.quote', bracket: '@open', next: '@string_dq' }],
+			[/'/, { token: 'string.quote', bracket: '@open', next: '@string_sq' }],
+
+			[/'[^\\']'/, 'string'],
+			[/(')(@escapes)(')/, ['string', 'string.escape', 'string']],
+			[/'/, 'string.invalid']
+		],
+		comment: [
+			[/[^\/*]+/, 'comment'],
+			[/\/\*/, 'comment', '@push'],    // nested comment
+			["\\*/", 'comment', '@pop'],
+			[/[\/*]/, 'comment']
+		],
+		comment2: [
+			[/[^\(*]+/, 'comment'],
+			[/\(\*/, 'comment', '@push'],    // nested comment
+			["\\*\\)", 'comment', '@pop'],
+			[/[\(*]/, 'comment']
+		],
+		whitespace: [
+			[/[ \t\r\n]+/, 'white'],
+			[/\/\/.*$/, 'comment'],
+			[/\/\*/, 'comment', '@comment'],
+			[/\(\*/, 'comment', '@comment2'],
+		],
+		string_dq: [
+			[/[^\\"]+/, 'string'],
+			[/@escapes/, 'string.escape'],
+			[/\\./, 'string.escape.invalid'],
+			[/"/, { token: 'string.quote', bracket: '@close', next: '@pop' }]
+		],
+		string_sq: [
+			[/[^\\']+/, 'string'],
+			[/@escapes/, 'string.escape'],
+			[/\\./, 'string.escape.invalid'],
+			[/'/, { token: 'string.quote', bracket: '@close', next: '@pop' }]
+		]
+	}
+};
diff --git a/test/setup.js b/test/setup.js
index f3a4c5a1..d797c473 100644
--- a/test/setup.js
+++ b/test/setup.js
@@ -64,6 +64,7 @@ define(['require'], function (require) {
 			'release/dev/redshift/redshift.test',
 			'release/dev/redis/redis.test',
 			'release/dev/csp/csp.test',
+			'release/dev/st/st.test',
 		], function () {
 			run(); // We can launch the tests!
 		}, function (err) {