Kołłątaj is a Polish language surname. It is commonly rendered into English without diacritics as Kollataj. The Russian language version is Kollontay.
The surname may refer to:
(1776–1794), nephew of Hugo , Polish-Lithuanian lieutenant Hugo Kołłątaj (1750–1812), Polish Roman Catholic priest, social and political activist, political thinker, historian and philosopher Kołłątaj's Forge, a group of activists and writers (1883–1944), Polish brigadier general (1750–1833), Polish nobleman and brother of Hugo