1991 U.S. Pro Indoor – Singles

Singles
1991 U.S. Pro Indoor
Champion Ivan Lendl
Runner-up Pete Sampras
Score5–7, 6–4, 6–4, 3–6, 6–3
Draw48
Seeds16

Pete Sampras was the defending champion.

Ivan Lendl won the title, defeating Sampras, 5–7, 6–4, 6–4, 3–6, 6–3 in the final.