8. c. 22) of Henry VIII's reign was passed by the Parliament of England in March 1534.

However, the legal calendar in use at that time dated the beginning of the year as March 25, and so considered the Act as being in 1533.

The Act made Elizabeth, daughter of Henry VIII by Anne Boleyn, who had been born on 7 September 1533, the heir presumptive to the Crown by declaring Mary, daughter of Henry VIII by Catherine of Aragon, a bastard.

The Act also required all subjects, if commanded, to swear an oath to recognize this Act as well as the king's supremacy.

The Act was later altered by the Second Succession Act, which made Elizabeth illegitimate, and the Third Succession Act, which returned both Mary and Elizabeth to the line of succession.