可可碱（英语：Theobromine）是一个甲基黄嘌呤类生物碱，存在于可可树和巧克力中。同属这一类的还有茶碱和咖啡因。其英文名称 theobromine 虽有 bromine 拼字，却不含溴元素，系因两者同样源于希腊文却是不同辞汇：前者希腊字根为 theo(神)+broma(食物)，后者的 brom- 则是另一希腊字 bromos(强臭味)，差别在此。

可可碱是苦味的无色或白色晶体，可溶于水，比其同系物咖啡因疗效低。它是茶碱和副黄嘌呤的同分异构体，属于二甲基黄嘌呤类。

1878年首先从可可树种子中提取出可可碱，不久之后赫尔曼·埃米尔·费歇尔完成了可可碱的合成。

Theobromine, formerly known as xantheose, is a bitter alkaloid of the cacao plant, with the chemical formula C₇H₈N₄O₂. It is found in chocolate, as well as in a number of other foods, including the leaves of the tea plant, and the kola (or cola) nut. It is classified as a xanthine alkaloid, which also include the similar compounds theophylline and caffeine. The compounds differ in their methylation.