May Slessinger (May 4, 1872 – October 25, 1954) was an American artist specializing in miniatures, based in San Francisco, California.

Her Bavarian-born father, a shoemaker by training, was an American Civil War veteran, and one of the city's first businessmen.

"[5] Slessinger made miniature portraits of several prominent San Francisco citizens, including artist William Keith, businesswoman Mary Ann Magnin and her son Grover Magnin, and Elizabeth Meyerfeld Roos, the daughter of theatrical entrepreneur Morris Meyerfeld Jr.[6][7][8] In 1920, Queen Marie of Romania named Slessinger her court miniaturist, in appreciation of Slessinger's portrait of the queen; dancer Loie Fuller, working with the Red Cross in Rumania during World War I, suggested Slessinger for the portrait commission.

[9] Slessinger married oil executive David S. Bachman in 1922, on his deathbed[10] and inherited half his fortune.

[13] Slessinger left a large estate to benefit her relatives and research at the Mount Zion Hospital.