The women's 400 metres hurdles sprint competition of the athletics events at the 2011 Pan American Games took place between the 24 and 26 of October at the Telmex Athletics Stadium.

[1] The defending Pan American Games champion was Sheena Johnson of the United States.

Prior to this competition, the existing world and Pan American Games records were as follows: Each National Olympic Committee (NOC) was able to enter one athlete regardless if they had met the qualification standard.

To enter two entrants both athletes had to have met the minimum standard (60.40) in the qualifying period (January 1, 2010 to September 14, 2011).

The first three in each heat and the next two fastest advanced to the finals.