| Event: | Swimming |
| Games: | 2018 South American Games |
| Venue: | G.A.M.C. Aquatics Center |
| Dates: | 27 May – 1 June |
| Nations: | 12 |
| Prev: | 2014 |
| Next: | 2022 |
The swimming competitions at the 2018 South American Games in Cochabamba took place from 27 to 30 May at the G.A.M.C. Aquatics Center at Mariscal Santa Cruz Park. Open water swimming events were held on 1 June at La Angostura Lake.
| 50m freestyle | Renzo Tjon-A-Joe | 22.65 | Cristian Quintero | 22.71 | André Calvelo | 22.80 | |
| 100m freestyle | Breno Correia | 49.40 | Cristian Quintero | 49.86 | Renzo Tjon-A-Joe | 50.12 | |
| 200m freestyle | Fernando Scheffer | 1:50.75 | Cristian Quintero | 1:50.89 | Benjamin Hockin | 1:52.03 | |
| 400m freestyle | Guilherme Costa | 3:57.31 | Rafael Davila | 3:58.92 | Esteban Enderica | 4:01.62 | |
| 1500m freestyle | Esteban Enderica | 15:38.16 | Guilherme Costa | 15:46.60 | Rafael Davila | 16:08.12 | |
| 100m backstroke | Gabriel Fantoni | 55.89 | Omar Pinzón | 56.31 | Charles Hockin | 56.65 | |
| 200m backstroke | Gabriel Fantoni | 2:04.41 | Matías López | 2:04.62 | Omar Pinzón | 2:05.37 | |
| 100m breaststroke | Jorge Murillo | 1:01.14 GR | Renato Prono | 1:02.10 | Carlos Mahecha | 1:03.13 | |
| 200m breaststroke | Jorge Murillo | 2:14.43 GR | Carlos Mahecha | 2:18.49 | Juan Sequera | 2:20.95 | |
| 100m butterfly | Kaue Carvalho | 53.90 | Esnaider Reales | 53.92 | Matheus Gonche | 54.41 | |
| 200m butterfly | Kaue Carvalho | 2:02.37 | David Arias | 2:03.37 | Miguel Armijos | 2:05.17 | |
| 200m individual medley | Omar Pinzón | 2:06.37 | Juan Sequera | 2:06.58 | Matías López | 2:06.96 | |
| 400m individual medley | Matías López | 4:38.76 | Andy Arteta | 4:46.15 | Gustavo Gutiérrez | 4:49.26 | |
| 4×100m freestyle relay | Jesus López (50.96) Bryan Chavez (49.70) Alberto Mestre Jr. (49.73) Cristian Quintero (49.13) | 3:19.52 | Marco Ferreira Júnior (50.90) Breno Correia (48.99) André Luiz de Souza (50.20) Fernando Scheffer (50.04) | 3:20.13 | Cardenio Fernández (52.25) Esnaider Reales (51.82) Carlos Mahecha (51.78) David Arias (51.67) | 3:27.52 | |
| 4×200m freestyle relay | Breno Correia (1:48.30) GR André Luiz de Souza (1:53.92) Kaue Carvalho (1:53.67) Fernando Scheffer (1:55.80) | 7:31.69 | Bryan Chavez (1:54.00) Andy Arteta (1:56.37) Rafael Davila (1:56.53) Cristian Quintero (1:52.89) | 7:39.79 | Juan Morales (1:55.01) Omar Pinzón (2:03.30) David Arias (1:57.16) Esnaider Reales (1:54,64) | 7:50.11 | |
| 4×100m medley relay | Omar Pinzón (56.24) Jorge Murillo (1:00.78) Esnaider Reales (54.12) Cardenio Fernández (51.69) | 3:42.83 | Gabriel Fanton (55.54) Yuri Vieira (1:04.34) Kaue Carvalho (53.93) Marco Ferreira Júnior (49.34) | 3:43.15 | Robinson Molina (57.81) Juan Sequera (1:03.08) Bryan Chavez (54.92) Cristian Quintero (49.18) | 3:44.99 | |
| 10 km open water | 1:52:01.52 | 1:52:19.89 | 1:54:50.94 | ||||
| 50m freestyle | 25.25 GR | 25.60 | 25.96 | ||||
| 100m freestyle | Isabella Arcila | 55.81 | Karen Torrez | 56.41 | Jeserik Pinto | 56.66 | |
| 200m freestyle | Gabrielle Roncatto | 2:04.61 | Rafaela Raurich | 2:04.80 | María Álvarez | 2:04.90 | |
| 400m freestyle | 4:19.58 | 4:25.70 | 4:25.88 | ||||
| 800m freestyle | 8:47.82 | 9:00.95 | 9:02.76 | ||||
| 100m backstroke | Isabella Arcila | 1:01.82 | Fernanda de Goeij | 1:02.94 | McKenna DeBever | 1:04.88 | |
| 200m backstroke | Andrea Hurtado | 2:19.13 | Fernanda de Goeij | 2:19.55 | Laura Melo | 2:22.94 | |
| 100m breaststroke | Ana Carolina Vieira | 1:11.59 | Mercedes Toledo | 1:11.83 | Bruna Monteiro Leme | 1:11.84 | |
| 200m breaststroke | Bruna Monteiro Leme | 2:35.67 | Beatriz Brandão Lysy | 2:35.79 | Mercedes Toledo | 2:37.16 | |
| 100m butterfly | Jeserik Pinto | 1:00.70 | Karen Torrez | 1:00.96 | Clarissa Rodrigues | 1:02.40 | |
| 200m butterfly | Beatriz Dizotti | 2:18.59 | Azra Avdic | 2:20.37 | María Román | 2:21.98 | |
| 200m individual medley | Gabrielle Roncatto | 2:20.11 | Bruna Monteiro Leme | 2:20.88 | McKenna DeBever | 2:21.25 | |
| 400m individual medley | 5:04.91 | 5:05.02 | 5:12.72 | ||||
| 4×100m freestyle relay | Ana Carolina Vieira (57.63) Camila Mello (56.70) Clarissa Rodrigues (58.00) Rafaela Raurich (57.88) | 3:50.21 | Valentina Becerra (59.94) Karen Durango (1:00.14) María Álvarez (58.24) Isabella Arcila (56.19) | 3:54.21 | Fabiana Pesce (1:00.35) Andrea Garrido (59.60) Mariangela Cincotti (1:00.35) Jeserik Pinto (56.11) | 3:56.41 | |
| 4×200m freestyle relay | 8:31.93 | Karen Durango (2:09.89) María Román (2:09.68) Isabella Arcila (2:07.67) María Álvarez (2:05.60) | 8:32.84 | Jessica Cattaneo (2:08.05) Azra Avdic (2:06.93) Andrea Hurtado (2:10.32) María Bramont-Arias (2:10.99) | 8:36.29 | ||
| 4×100m medley relay | Fernanda de Goeij (1:03.61) Ana Carolina Vieira (1:11.40) Clarissa Rodrigues (1:02.06) Rafaela Raurich (56.61) | 4:13.68 | Isabella Arcila (1:02.57) Karina Vivas (1:11.53) Valentina Becerra (1:02.55) María Álvarez (57.68) | 4:14.33 | Andrea Hurtado (1:06.76) McKenna DeBever (1:16.30) Azra Avdic (1:04.81) Jessica Cattaneo (58.63) | 4:26.50 | |
| 10 km open water | 2:05:49 | 2:06:47 | 2:10:25 | ||||