James, Jim, or Jamie Mayer may refer to:

• James W. Mayer (1930–2013), American applied physicist
• James Mayer (spy) (1920–1944), Mauritian secret agent during World War II
• Jim Mayer (musician) (born c. 1961), American guitarist, singer-songwriter, and producer
• James Erskine Mayer (1889–1957), American baseball player with the Philadelphia Phillies, the Pittsburgh Pirates, and the Chicago White Sox
• Jamie Mayer (born 1977), Scottish former professional rugby player
• Jim Mayer (ice hockey) (born 1954), Canadian ice hockey player