The women's 100 metre backstroke competition of the swimming events at the 1955 Pan American Games took place on 24 March.

[1][2] The last Pan American Games champion was Maureen O'Brien of US.

[3][4][5][6][7] This race consisted of two lengths of the pool, all in backstroke.

[8] All times are in minutes and seconds.

The final was held on March 24.