天南星科（学名：Araceae）是单子叶开花植物中的一科，有107属、3700个以上的物种，主要分布在新世界的热带地区，但也有些分布于旧世界的热带及温带地区。中国有35属约206种，主要分布在南方各地。**产16属40种，有4种记录为杂草。由APG最近的基因研究显示，原先独立归于浮萍科的植物，也应归类于天南星科之中。

火鹤花与马蹄莲是本科有名的植物，常被栽培供观赏用。粗肋草、观音莲、彩叶芋、黛粉叶、黄金葛、龟背芋、蔓绿绒、白鹤芋、合果芋、千年芋、美铁芋等耐阴性强的观叶植物可以做室内植物栽培。芋头、魔芋地下块茎可以加工做成蒟蒻，可以食用。半夏、天南星、千年健、犁头尖可做药用。水榕、隐棒花、水芭蕉、大萍等水生植物可做水族造景。巨花魔芋是全世界最高的花，其花序是植物界中最长的花序。姑婆芋是一种很有名的野生植物，其植株具毒性。

The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe or leaf-like bract. Also known as the arum family, members are often colloquially known as aroids. This family of 107 genera and over 3700 species is most diverse in the New World tropics, although also distributed in the Old World tropics and northern temperate regions.