Robert, Bob or Rob May may refer to:
- Robert May (cook) (1588 – c. 1664), English chef
- Robert May (producer) American filmmaker, producer and director
- Robert May, founder in 1694 of Robert May's School, Odiham, Hampshire, England
- Robert C. May, American philosopher
- Robert G. May, American academic administrator
- Robert H. May (1822–1903), mayor of Augusta, Georgia
- Robert Hobart May (c.1801–?1832), Aboriginal Tasmanian massacre survivor
- Robert L. May (1905–1976), creator of Rudolph the Red-Nosed Reindeer
- Robert P. May, interim CEO of HealthSouth Corporation
- Robert May, Baron May of Oxford (1936–2020), Australian biologist
- Bob May (actor) (1939–2009), American actor
- Bob May (golfer) (born 1968), American professional golfer
- Bob May (ice hockey) (1927–2014), Canadian ice hockey player and coach
- Bob May (politician) (1909–1986), Australian politician
- Rob May (born 1969), English musician