Darlene Ruth Hard (January 6, 1936 – December 2, 2021) was an American professional tennis player, known for her aggressive volleying ability and strong serves.

According to Lance Tingay, Hard was ranked among the top 10 in the world from 1957 through 1963, reaching a career high of No.

[4] Hard was included in the year-end top-10 rankings issued by the United States Lawn Tennis Association from 1954 through 1963.

[6] With her younger doubles partner Billie Jean King, she helped the US team to victory in the 1963 Federation Cup.

[10][4] In 1964, Hard won the singles title at the South African Championships, defeating Ann Haydon-Jones in the final in straight sets, and soon afterwards turned professional when she became a teaching pro.