The men's decathlon competition featured as part of the athletics programme at the 1968 Summer Olympics and was held at the Estadio Olímpico Universitario in Mexico City on 18 and 19 October.

American Bill Toomey won the gold medal with an Olympic record score of 8193 points.

Two West German athletes, Hans-Joachim Walde and Kurt Bendlin, took the silver and bronze medals, respectively.

A total of 33 competitors from 20 nations entered the decathlon with 19 athletes managing to finish all events at the competition.

The sixth-placer Tom Waddell, representing the United States, later went on to found the Gay Olympics.