The men's 100 metres was the shortest of the men's track races in the Athletics at the 1964 Summer Olympics program in Tokyo, Japan. It was held at the Olympic Stadium on 14 and 15 October 1964. 76 athletes from 49 nations entered, with 3 not starting in the first round. Nations were limited to three athletes each, per rules in force since the 1930 Olympic Congress. The first two rounds were held on 14 October, with the semifinals and the final on the following day.

At the 1964 Summer Olympics in Tokyo, the athletics competition included 36 events, 24 for men and 12 for women. The women's 400 metres and women's pentathlon events were newly introduced at these Games. There were a total number of 1016 participating athletes from 82 countries.