The Catholic Relief Act 1829, also known as the Catholic Emancipation Act 1829, was passed by the Parliament of the United Kingdom in 1829. It was the culmination of the process of Catholic Emancipation throughout the United Kingdom of Great Britain and Ireland. In Ireland, it repealed the Test Act 1672 and the remaining Penal Laws which had been in force since the passing of the Disenfranchising Act of the Irish Parliament of 1728. Its passage followed a vigorous campaign that threatened insurrection led by Irish lawyer Daniel O'Connell. The British leaders, the prime minister the Duke of Wellington and his top aide Robert Peel, although initially opposed, gave in to avoid civil strife.

The act permitted members of the Catholic Church to sit in the parliament at Westminster. O'Connell had won a seat in a by-election for Clare in 1828 against an Anglican. Under the then-extant penal law, O'Connell, as a Catholic, was forbidden to take his seat in Parliament. Peel, the Home Secretary, until then was called "Orange Peel" because he always supported the Orange (anti-Catholic) position. Peel now concluded: "though emancipation was a great danger, civil strife was a greater danger." Fearing a revolution in Ireland, Peel drew up the Catholic Relief Bill and guided it through the House of Commons. To overcome the vehement opposition of both the House of Lords and King George IV, the Duke of Wellington worked tirelessly to ensure passage in the House of Lords, and threatened to resign as prime minister if the king did not give royal assent.