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 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