The 1991 Mazda Classic was a women's tennis tournament played on outdoor hard courts at the La Costa Resort and Spa in San Diego, California, in the United States that was part of Tier III of the 1991 WTA Tour.

Fourth-seeded Jennifer Capriati won the singles title and earned $45,000 first-prize money.

It was the tournament's first year in La Costa after moving from the San Diego Tennis & Racquet Club.

It was also Mazda's first year as sponsor after replacing Great American Bank, a San Diego–based institution that was in financial decline.

[1] Jennifer Capriati defeated Monica Seles, 4–6, 6–1, 7–6(7–2) Jill Hetherington / Kathy Rinaldi defeated Gigi Fernández / Nathalie Tauziat, 6–4, 3–6, 6–2