Bertha Louise Townsend Toulmin (née Townsend; March 7, 1869 – May 12, 1909) was a female tennis player from the United States.

She is best remembered for being the first repeating women's singles champion at the U.S. Championships (now U.S. Open) in 1888 and 1889.

[1] She developed the underhand technique.

She was inducted into the International Tennis Hall of Fame in 1974.

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