The men's 400 metre freestyle competition of the swimming events at the 1973 World Aquatics Championships took place on September 6.

Records

Prior to the competition, the existing world and championship records were as follows. The following records were established during the competition:

Results

27 swimmers participated in 4 heats.

The results of the final are below.

{{DEFAULTSORT:Swimming at the 1973 World Aquatics Championships - Men's 400 metre freestyle Freestyle 0400 metre, men's World Aquatics Championships