William May may refer to:
- William May (cricketer) (died 1888), English cricketer
- William W. May (1887–1979), American Olympic sprinter
- Bill May (American football) (active 1913–1915), American football player
- Bill May (American football, born 1913) (1913–2004), American football player
- Bill May (synchronized swimmer) (born 1979), American synchronized swimmer
- Bill May (soccer) (born 1974), retired American soccer goalkeeper
- Billy May (footballer) (1865–1936), English footballer
- Willie May (1936–2012), American hurdler
- Buckshot May (William Herbert May, 1899–1984), American baseball player
- William May (pirate) (fl. 1690–1700), privateer and pirate active in the Indian Ocean
- William May (artistic director) (1953–2009), American-born Australian artistic director, creator of Walking with Dinosaurs - The Live Experience
- William F. May (chemical engineer) (1915–2011), American co-founder of the Film Society of Lincoln Center
- William F. May (ethicist) (born 1927), American ethicist
- William May (Royal Navy officer) (1849–1930), British admiral active in 1910s
- William Charles May (1853–1931), English sculptor and painter
- Billy May (1916–2004), American composer, arranger and musician
- Willie E. May, American chemist and standards and technology administrator