组蛋白H1（英语：Histone H1）是组成真核细胞染色质的五种主要的组蛋白家族中的一种。尽管这种组蛋白是高度保守的，但在各物种间其串行变异性仍是所有组蛋白中最大的。

Histone H1 is one of the five main histone protein families which are components of chromatin in eukaryotic cells. Though highly conserved, it is nevertheless the most variable histone in sequence across species.