无患子科（学名：Sapindaceae）是无患子目的一个科。近期的分类系统（APG分类法）主张将槭树科和七叶树科这两个科并入到无患子科内。无患子科约有140-150属，1400-2000种。中国有27属约250多种，分布在全国各地。

相传以无患树的木材制成的木棒可以驱魔杀鬼，因此名为无患。无患子拉丁学名Sapindus是soap indicus的缩写，意思是"印度的肥皂"，因为它那厚肉质状的果皮含有皂素，只要用水搓揉便会产生泡沫。

本科植物为乔木、灌木、草本或藤本。分布于全世界，由温带至热带地区均有分布。多具有乳汁，在叶子或种子内含有微毒的皂素。

Sapindaceae, also known as the soapberry family, is a family of flowering plants in the order Sapindales. There are about 140–150 genera with 1400–2000 species, including maple, horse chestnut, and lychee.

Sapindaceae members occur in temperate to tropical regions, many in laurel forest habitat, throughout the world. Many are laticiferous, i.e. they contain latex, a milky sap, and many contain mildly toxic saponins with soap-like qualities in either the foliage and/or the seeds, or roots. The largest genera are Serjania, Paullinia, Acer and Allophylus.