Mercedes María Paz (Spanish pronunciation: [meɾˈseðes maˈɾi.a ˈpas]; born 27 June 1966) is a former professional tennis player from Argentina.

She won three singles titles on the WTA Tour and reached a career-high ranking of world No.

Paz unexpectedly defeated defending champion Arantxa Sánchez Vicario in the second round of the 1990 French Open.

In addition to wins over Sánchez Vicario and Sabatini, she also defeated top-seeded Jana Novotná in three sets to reach the semifinals of the Belgian Ladies Open in Brussels in 1989.

The previous year, at the 1988 Hilton Head tournament, Paz had defeated Novotná in the round of 32 for the first time.