小天鹅（学名：Cygnus columbianus），又名鹄或白鹄，是一种体型比大天鹅小的天鹅。

喜欢在泥泞水塘、湖泊或泥滩等生境中活动，常在水中缓慢前进，嘴往两旁甩动以寻找食物。

The tundra swan (Cygnus columbianus) is a small Holarctic swan. The two taxa within it are usually regarded as conspecific, but are also sometimes split into two species: Bewick's swan (Cygnus bewickii) of the Palaearctic and the whistling swan (C. columbianus) proper of the Nearctic. Birds from eastern Russia (roughly east of the Taimyr Peninsula) are sometimes separated as the subspecies C. c. jankowskii, but this is not widely accepted as distinct, most authors including them in C. c. bewickii. Tundra swans are sometimes separated in the genus Olor together with the other Arctic swan species.