The men's 400 metres hurdles event at the 1952 Summer Olympics took place July 20–21, 1952 at the Helsinki Olympic Stadium. There were 40 competitors from 24 nations. The maximum number of athletes per nation had been set at 3 since the 1930 Olympic Congress. The final was won by American Charles Moore. It was the nation's third consecutive and eighth overall victory in the event. The Soviet Union, in its debut, and New Zealand each earned their first medal in the men's 400 metres hurdles, with Yuriy Lituyev's silver and John Holland's bronze, respectively.