James I may refer to:

• James I of Aragon (1208–1276)
• James I of Sicily or James II of Aragon (1267–1327)
• James I, Count of La Marche (1319–1362), Count of Ponthieu
• James I, Count of Urgell (1321–1347)
• James I of Cyprus (1334–1398), also titular king of Armenia and Jerusalem
• James I of Scotland (1394–1437)
• James VI and I (1566–1625), King of Scotland and also King of England and Ireland
• James Harden-Hickey or James I (1893–1895), self-declared Prince James I of Trinidad

• James 1, the first chapter of the Epistle of James
• James I Land, Spitsbergen, Svalbard

• James (disambiguation)
• James II (disambiguation)
• James III (disambiguation)
• James IV of Scotland
• James V of Scotland