Swimming at the 1964 Summer Olympics – Men's 400 metre freestyle

The men's 400 metre freestyle event at the 1964 Olympic Games took place between October 14 and 15. This swimming event used freestyle swimming, which means that the method of the stroke is not regulated (unlike backstroke, breaststroke, and butterfly events). Nearly all swimmers use the front crawl or a variant of that stroke. Because an Olympic size swimming pool is 50 metres long, this race consisted of eight lengths of the pool.

Heats
Seven heats were held; the fastest eight swimmers advanced to the Finals. Those that advanced are highlighted.

Final
Key: WR = World record