The men's (outdoor) singles was one of six lawn tennis events on the Tennis at the 1908 Summer Olympics programme. The tournament was played on grass courts at the All England Lawn Tennis and Croquet Club. There were 31 competitors from 9 nations. Nations could enter up to 12 players. The event was won by Major Ritchie of Great Britain, the nation's third victory in four Games. Otto Froitzheim earned Germany's first medal in the event with his silver. Another Briton, Wilberforce Eaves, took bronze.

Six tennis events were contested at the 1908 Summer Olympics in London, United Kingdom. Indoor tennis events, on what were officially called 'covered courts', were held for the first time, along with the usual outdoor events. Women's events were contested, with women's singles and indoor women's singles. The indoor events were held at the covered courts of the Queen's Club and began on 6 May 1908, ahead of the official start of the Games while the outdoor tournament was played on grass courts at the All England Lawn Tennis and Croquet Club at Worple Road from 6 July through 11 July 1908. In total 50 players, 40 men and 10 women, competed. Five nations made their tennis debuts, while five more returned to competition for a total of ten nations. Two players, Les Poidevin and Wimbledon champion Anthony Wilding were nominated for Australasia but through administrative bungling they were not entered.