Ambesse Tolosa (born 28 August 1977 in Shewa) is an Ethiopian long-distance runner, who specializes in the marathon race. Tolosa tested positive for banned substances in February 2008 and received a two-year ban from competitive athletics. The substance that was present in his system (morphine) was not a performance-enhancing drug and Tolosa said that he did not know how it had gotten into his body, but the IAAF rules stated that athletes received bans regardless of intent. His results from 9 December 2007 onwards were annulled, which included his win at the Honolulu Marathon that year.