See main article: 1963 Pan American Games.
The Swimming competition at the 4th Pan American Games was held in São Paulo, Brazil during the Games' run in 1963. It consisted of 16 long course (50m) events: 8 for males and 8 for females.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
In these Games, the U.S. earned all gold medals that were in dispute in swimming.
Venezuela won for the first time a medal, a bronze in the women's 4x100m medley relay.
| 100m freestyle | Steve Clark  USA | 54.7 | Steven Jackman USA | 54.8 | Daniel Sherry  Canada | 56.1 |
| 400m freestyle | Roy Saari USA | 4:19.3 | Don Schollander USA | 4:23.3 | Sandy Gilchrist Canada | 4:29.1 |
| 1500m freestyle | Roy Saari USA | 17:26.2 | Sandy Gilchrist Canada | 17:58.9 | Ralph Hutton Canada | 18:08.6 |
| 100m backstroke | Ed Bartsch USA | 1:01.5 | Charles Bittick USA | 1:02.1 | Athos de Oliveira  Brazil | 1:03.2 |
| 200m breaststroke | Chet Jastremski USA | 2:35.4 | Ken Merten USA | 2:38.4 | John Kelso Canada | 2:41.4 |
| 200m butterfly | Carl Robie USA | 2:11.3 | Fred Schmidt USA | 2:13.3 | Luis Nicolao  Argentina | 2:16.1 |
| 4×200m free Relay | Gary Ilman Richard McDonough David Lyons Ed Townsend | 8:16.9 | Ralph Hutton Aldwin Meinhardt Ed Casalet Sandy Gilchrist | 8:33.0 | Athos de Oliveira Antonio Renzo Filho Antonio Celso Guimarães Peter Wolfgang Metzner | 8:41.4 |
| 4×100m medley Relay | Richard McGeagh Bill Craig Walter Richardson Nicholas Kirby | 4:05.6 | Carlos Van der Maath Alberto Pérez Luis Nicolao Abel Pepe | 4:17.3 | Ed Casalet John Kelso Daniel Sherry Sandy Gilchrist | 4:17.5 |
| 100m freestyle | Terri Stickles USA | 1:02.8 | Mary Stewart Canada | 1:03.3 | Kathleen Ellis USA | 1:03.5 |
| 200m freestyle | Robyn Johnson USA | 2:17.5 | Terri Stickles USA | 2:18.4 | Lynne Pomfret Canada | 2:28.4 |
| 400m freestyle | Sharon Finneran USA | 4:52.7 | Robyn Johnson USA | 4:56.1 | Lynne Pomfret Canada | 5:20.4 |
| 100m backstroke | Nina Harmer USA | 1:11.5 | Cathy Ferguson USA | 1:13.1 | Eileen Weir Canada | 1:14.5 |
| 200m breaststroke | Alice Driscoll USA | 2:56.2 | Roby Whipple USA | 2:57.7 | Marjon Wilmink Canada | 3:00.0 |
| 100m butterfly | Kathleen Ellis USA | 1:07.6 | Mary Stewart Canada | 1:08.9 | Kim Worley USA | 1:11.6 |
| 4×100m free Relay | Elizabeth MacCleary Sharon Stouder Judy Norton Donna de Varona | 4:15.7 | Lynne Pomfret Sharon Pierce Eileen Weir Mary Stewart | 4:31.7 | Eliana Souza Motta Maria Lourdes Teixeira Angela Maria Palioli Vera Maria Formiga | 4:34.3 |
| 4×100m medley Relay | Ginny Duenkel Cynthia Goyette Sharon Stouder Donna de Varona | 4:49.1 | Mary Stewart Madelaine Sevigny Sharon Pierce Lynne Pomfret | 4:52.5 | Bettina Giller Luisa Ruiz Laura Varela Anneliese Rockenback | 5:11.8 |