| Event: | Men's 100 metre backstroke |
| Games: | 2011 |
| Venue: | Scotiabank Aquatics Center |
| Dates: | October 17 (preliminaries and finals) |
| Competitors: | 11 |
| Nations: | 8 |
| Win Label: | Winning score |
| Gold: | Thiago Pereira |
| Goldnoc: | BRA |
| Silver: | Eugene Godsoe |
| Silvernoc: | USA |
| Bronze: | Guilherme Guido |
| Bronzenoc: | BRA |
| Prev: | 2007 |
| Next: | 2015 |
The men's 100 metre backstroke competition of the swimming events at the 2011 Pan American Games took place on October 17 at the Scotiabank Aquatics Center in the municipality of Zapopan, near Guadalajara, Mexico.[1] The defending Pan American Games champion was Randall Bal of the United States
This race consisted of two lengths of the pool, all in backstroke.[2]
Prior to this competition, the existing world and Pan American Games records were as follows:
| World record | 51.94 | Indianapolis, United States | July 8, 2009 | ||
| Pan American Games record | 53.66 | Rio de Janeiro, Brazil | July 22, 2007 |
Each National Olympic Committee (NOC) was able to enter up to two entrants providing they had met the A standard (56.7) in the qualifying period (January 1, 2010 to September 4, 2011). NOCs were also permitted to enter one athlete providing they had met the B standard (58.6) in the same qualifying period.[2]
All times are in minutes and seconds.
The first round was held on October 17.
| Rank | Heat | Lane | Name | Nationality | Time[3] | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 4 | align=left | align=left | 55.04 | QA | |||
| 2 | 2 | 5 | align=left | align=left | 55.50 | QA | |||
| 3 | 1 | 4 | align=left | align=left | 55.57 | QA | |||
| 4 | 1 | 5 | align=left | align=left | 55.71 | QA | |||
| 5 | 1 | 3 | align=left | align=left | 56.00 | QA | |||
| 6 | 2 | 6 | align=left | align=left | 56.71 | QA | |||
| 7 | 2 | 3 | align=left | align=left | 56.82 | QA | |||
| 8 | 1 | 6 | align=left | align=left | 57.61 | QA | |||
| 9 | 1 | 2 | align=left | align=left | 57.65 | QB | |||
| 10 | 2 | 7 | align=left | align=left | 57.93 | QB | |||
| 11 | 2 | 2 | align=left | align=left | 59.29 | QB |
The B final was also held on October 17.[4]
| Rank | Lane | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|
| 9 | 4 | align=left | align=left | 58.29 | ||||
| 10 | 5 | align=left | align=left | 59.11 |
The A final was also held on October 17.
| Rank | Lane | Name | Nationality | Time[5] | Notes | |||
|---|---|---|---|---|---|---|---|---|
| 5 | align=left | align=left | 54.56 | |||||
| 4 | align=left | align=left | 54.61 | |||||
| 6 | align=left | align=left | 54.81 | |||||
| 4 | 3 | align=left | align=left | 54.87 | ||||
| 5 | 2 | align=left | align=left | 55.22 | ||||
| 6 | 7 | align=left | align=left | 56.16 | ||||
| 7 | 1 | align=left | align=left | 57.54 | ||||
| 8 | 8 | align=left | align=left | 57.63 |