锌指（英语：Zinc finger），又称锌手指。是在很多蛋白中存在的一类具有指状结构的结构模体，这些具有锌指结构的蛋白大多都是与基因表达的调控有关的功能蛋白。

锌指结构的共同特征是通过肽链中氨基酸残基的特征基团与Zn的结合来稳定一种很短的，可自我折叠成“手指”形状的的多肽空间构型。

最初发现的锌指蛋白是非洲爪蟾卵母细胞中的转录因子IIIA，已知广泛分布在动物、植物和微生物中，人类基因组中可能有将近1％的串行编码的是含有锌指结构的蛋白质，目前人们已经清楚地知道锌指结构是识别特定碱基串行的一种普遍性的转录因子结构。

A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions in order to stabilize the fold. Originally coined to describe the finger-like appearance of a hypothesized structure from Xenopus laevis transcription factor IIIA, the zinc finger name has now come to encompass a wide variety of differing protein structures. Xenopus laevis TFIIIA was originally demonstrated to contain zinc and require the metal for function in 1983, the first such reported zinc requirement for a gene regulatory protein.