The men's 100 metre backstroke competition of the swimming events at the 1971 Pan American Games took place on 6 August.

[1][2] The last Pan American Games champion was José Fiolo of Brazil.

[3][4][5][6][7][8] This race consisted of two lengths of the pool, both lengths being in breaststroke.

[9] All times are in minutes and seconds.

The final was held on August 6.