Assefa Mezgebu (born June 19, 1978 in Sidamo) is a retired Ethiopian long-distance runner, best known for winning a bronze medal in the 10,000 metres event at the 2000 Summer Olympics.

He was also the runner-up at the 2001 World Championships in Athletics, following a bronze medal at the 1999 World Championships in Athletics.

He also competed in cross-country running and reached the podium at the IAAF World Cross Country Championships in 1998 and 2000.

Assefa Mezgebu is the younger brother of Ayele Mezgebu.

This biographical article relating to Ethiopian athletics is a stub.