Castrén is the surname of a Finnish family. Notable members include
- Matthias Alexander Castrén (1813 - 1853), a Finnish ethnologist and philologist.
- Kaarlo Castrén (1860 - 1938), Prime Minister of Finland.
- Erik Castrén Institute of International Law and Human Rights
Castrén is a football stadium in the Välivainio neighbourhood of Oulu, Finland. The stadium holds 4 000 spectators. It is the home ground of sports clubs Oulun Luistinseura, JS Hercules and Oulun Palloseura.