The women's 100 metre breaststroke 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 Michelle McKeehan of the United States.

[2] Prior to this competition, the existing world and Pan American Games records were as follows: Each National Olympic Committee (NOC) was able to enter up to two entrants, providing they had met the A standard (1:13.3) 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 (1:15.5) in the same qualifying period.

[2] All times are in minutes and seconds.