Men's 400 metre freestyle at the I959 Pan American Games
Venue	-
Dates	September 1 (preliminaries), September 3 (finals)
Medalists
George Breen   United States   George Harrison   United States   Eugene Lenz   United States
«1955 1963»

The men's 400 metre freestyle competition of the swimming events at the 1959 Pan American Games took place on 1 September (preliminaires)^[1][2] and 3 September (finals).^[3] The last Pan American Games champion was James McLane of US.^[4][5][6][7]

This race consisted of eight lengths of the pool, with all eight being in the freestyle stroke.^[8]

All times are in minutes and seconds.

The first round was held on September 1.^[1]

Rank	Heat	Name	Nationality	Time	Notes
1	1	George Harrison	United States	4:34.1	Q, GR
-	2	Eugene Lenz	United States	4:37.2	Q
-	1	Alfredo Guzmán	Mexico	-	Q
-	2	Mauricio Ocampo	Mexico	-	Q
-	4	Sídnei Gavioli	Brazil	4:44.9	Q
-	3	George Breen	United States	4:46.4	Q
-	4	Jorge Escalante	Mexico	-	Q
-	-	-	-	-	Q
-	-	Francisco Carioba	Brazil	-

The final was held on September 3.^[3]

Rank	Name	Nationality	Time	Notes
	George Breen	United States	4:31.4	GR
	George Harrison	United States	4:31.8
	Eugene Lenz	United States	4:34.9
4	Mauricio Ocampo	Mexico	4:42.4
5	Alfredo Guzmán	Mexico	4:42.7
6	Jorge Escalante	Mexico	4:49.9
7	-	-	-
8	Sídnei Gavioli	Brazil	4:50.2