The Succession to the Crown Act 1603 (1 Jas. 1. c. 1), full title A most joyful and just recognition of the immediate, lawful and undoubted Succession, Descent and Right of the Crown, was an act of the Parliament of England enacted during the reign of James I. The act recited the loyalty of Parliament to James, and stated that the English crown, on the death of Elizabeth I, had come to him "by inherent birthright and lawful and undoubted succession", and acknowledged him as the legitimate king "of England, Scotland, France and Ireland".
The whole act was repealed by section 1 of, and the first schedule to, the Statute Law Revision Act 1948 (11 & 12 Geo. 6. c. 62), having become obsolete in the intervening three centuries.