The 1988 Northern California Open singles was a tennis competition, part of the 1988 Northern California Open organised by the Women's Tennis Association.

It was played on outdoor hard courts in Aptos, California[1] in the United States and was part of Tier V of the 1988 WTA Tour.

Elly Hakami was the defending champion, but lost in the first round to Jennifer Santrock.

Sara Gomer won in the final 6–4, 7–5 against Robin White.

A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.