James Dillon may refer to:

• James Dillon (officer) (c. 1600 - after 1669), Irish Confederate officer
• James Dillon (bishop) (1738–1806), Roman Catholic Bishop of Kilmore, Ireland
• James Dillon (Irish senator) (died 1955), farmer who served in the Senate of the Irish Free State
• James Dillon (Fine Gael politician) (1902–1986), Irish politician and leader of the Fine Gael party
• James Dillon, 3rd Earl of Roscommon (c. 1605–1649), leader of the Royalist forces in Ireland
• James Dillon (composer) (born 1950), Scottish composer often regarded as belonging to the New Complexity school
• James Dillon (Australian politician) (1880–1949), Victorian State politician for the electoral district of Essendon
• James J. Dillon (born 1942), retired American professional wrestler and manager
• James Dillon (production designer), British production designer
• James Dillon, 1st Earl of Roscommon (died 1642), Irish peer

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