The Clethraceae are a small family of flowering plants in the order Ericales, native to warm temperate to tropical regions of Asia and the Americas, with one species also on Madeira. The family comprises two genera, Clethra and Purdiaea.

In the past, most botanists included only Clethra in the family, but recent research has shown Purdiaea, previously placed in the closely related family Cyrillaceae, is more closely allied to Clethra.