耀西（日文：ヨッシー，英文：Yoshi），是任天堂公司的游戏系列之一虚构角色。

耀西是于玛利欧游戏系列活跃之一种恐龙，也是系列主角玛利欧的好朋友。玛利欧兄弟与青绿色耀西从他们婴孩时期已经认识，这在《耀西岛》游戏系列清楚说明。值得注意的是，「耀西」一名可以是指整族恐龙或单一个体（用於单一个体时指青绿色的耀西）。

普遍出现于屏幕前的耀西是一只青绿色恐龙，下巴、胸腹之尾巴下方则为白色，后枕的位置有红色角状物，背脊也有一红色的壳，穿着一对红色的鞋子（在一些版本中为橙色）。大鼻子更是牠一大特征，另外，耀西有一条能伸长又黏答答的舌头，在多项玛利欧游戏中，牠都利用舌头抓住某些敌人，耀西可以吐出敌人或吞下敌人产卵，在《耀西岛》等游戏中，牠能利用这些蛋进行攻击或取得物品。

Yoshi(ヨッシー,Yosshī, [jo.ɕːiː]) (English: /ˈjoʊʃi/ or /ˈjɒʃi/), once romanized as Yossy, is a fictional anthropomorphic dinosaur (referred to as a dragon at times) who appears in video games published by Nintendo. Yoshi debuted in Super Mario World (1990) on the Super Nintendo Entertainment System as Mario and Luigi's sidekick (a role often reprised by Yoshi), and later starred in platform and puzzle games, including Super Mario World 2: Yoshi's Island and Yoshi's Story and Yoshi's Woolly World. Yoshi has also appeared in many of the spin-off Mario series including Mario Party, Mario Kart, and Super Smash Bros., as well as in various Mario sports titles. Yoshi belongs to the species of the same name which comes in various colors, with green being the most common.