冬荫（泰语：ต้มยำ，[tôm.jām]，老挝文：ຕົ້ມຍຳ，老挝语发音： [tôm.ɲám]），也称为泰式酸辣汤，港澳人士多称为冬荫功，是一道著名的泰国酸辣汤，由南姜、酸子、香茅、青葱、酸柠檬、辣椒和鱼露调制而成。

当中最著名的是加虾和草菇、以鱼露调味并形成乳状质感的冬荫功（ต้มยำกุ้ง，音tom yum gung）。另外有鸡肉汤（ต้มยำไก่，音tom yum gai）、海鲜汤（ต้มยำทะเล，音tom yum taleh）等。加入椰子汁的称为ต้มยำน้ำข้น（音tom yum num khon）。

Tom yum, rtgs: tom yam, Thai:ต้มยำ,  [tôm.jām]) is a Thai soup, usually cooked with shrimp. Tom yum is widely served in neighbouring countries such as Cambodia, Brunei, Malaysia and Singapore, and has been popularised around the world.

Literally, the words "tom yam" are derived from two Thai words: "tom" and "yam". "Tom" refers to boiling process, while "yam" refers to a Thai spicy and sour salad. Indeed, tom yum is characterised by its distinct hot and sour flavours, with fragrant spices and herbs generously used in the broth. The basic broth is made of stock and fresh ingredients such as lemongrass, kaffir lime leaves, galangal, lime juice, fish sauce, and crushed chili peppers.