Kaarel Oja (born on April 21, 1985) is an Estonian politician and cultural organizer, since 2021 the deputy mayor of Tallinn.

He is a member of the Social Democratic Party. He has worked as the CEO of Teater NO99 and Vaba Lava and managed the educational materials publishing house Maurus.

Kaarel Oja has been married to actress Ursula Ratasepp-Oja since 2010, the family has three children. His brother is the actor Pääru Oja and his father is the actor Tõnu Oja.