The women's 100 metre butterfly competition of the swimming events at the 1971 Pan American Games took place on 8 August.

[1][2] The last Pan American Games champion was Ellie Daniel of US.

[3][4][5][6][7][8][excessive citations] This race consisted of two lengths of the pool, all in butterfly.

[9] All times are in minutes and seconds.

The final was held on August 8.