Donald Lynden-Bell CBE FRS (born 5 April 1935) is an English astrophysicist, best known for his theories that galaxies contain massive black holes at their centre, and that such black holes are the principal source of energy in quasars. He was a co-recipient, with Maarten Schmidt, of the inaugural Kavli Prize for Astrophysics in 2008. Lynden-Bell has been the president of the Royal Astronomical Society.