George Foreman lost to the following notable opponents during his professional boxing career:

• Muhammad Ali: Foreman lost by knockout in the famous "Rumble in the Jungle" fight on October 30, 1974, where Ali regained the heavyweight title from Foreman

• Jimmy Young: Foreman lost by unanimous decision in 1977

• Evander Holyfield: Foreman lost by unanimous decision in 1991

• Tommy Morrison: Foreman lost by unanimous decision in 1993

• Shannon Briggs: Foreman lost by majority decision in 1997, which was his final professional fight before retiring

In total, Foreman had five losses in his career, with four by decision and one by knockout to Muhammad Ali