James Reilly may refer to:

• James Reilly (Canadian politician) (1835–1909), Canadian businessman and Mayor of Calgary
• James Reilly (Irish politician) (born 1955), Irish Fine Gael politician
• James Reilly (swimmer) (1890–1962), American swimmer
• James Bernard Reilly (1845–1924), U.S. Representative from Pennsylvania
• James E. Reilly (1948–2008), American television scriptwriter
• James F. Reilly (born 1954), American astronaut and geologist, director of the U.S. Geological Survey
• James Marshall Reilly (born 1981), American entrepreneur, author and public speaker
• James W. Reilly (1828–1905), American Civil War general in the Union Army and Ohio state representative
• Jim Reilly (born 1957), drummer for punk band Stiff Little Fingers
• Jim Reilly (American football) (1948–1994), American football player
• Jim Reilly (Gaelic footballer) (1924–2013), Irish footballer
• Jim Reilly (Illinois politician) (1945–2022), American politician from Illinois
• Joe Reilly (baseball) (James Reilly, 1861–?), American baseball player