The Buggery Act 1533, formally An Acte for the punishment of the vice of Buggerie (25 Hen. 8. c. 6), was an act of the Parliament of England that was passed during the reign of Henry VIII.

The act was the country's first civil sodomy law, such offences having previously been dealt with by the ecclesiastical courts.

The term buggery, not defined in the text of the legislation, was later interpreted by the courts to include only anal penetration and bestiality, regardless of the sex of the participants, but not oral penetration. The act remained in force until it was repealed and replaced by the Offences Against the Person Act 1828 (9 Geo. 4. c. 31). Buggery remained a capital offence until 1861, though the last executions were in 1835.

The act was piloted through Parliament by Henry VIII's minister Thomas Cromwell (though it is unrecorded who actually wrote the bill), and punished "the detestable and abominable Vice of Buggery committed with Mankind or Beast". Prior to the 1550s, the term "Buggery" was not used in a homosexual sense, rather related to any sexual activity not related to procreation, regardless of sex or species involved in the sexual act, and also covered sexual crimes of a non-consensual nature. The law was not designed to police sexual activity, rather was simply taking a canon law and making it a civil law, a test case in removing church power. "Buggery" was not further defined in the law. According to the act:

This meant that a convicted sodomite's possessions could be confiscated by the government, rather than going to their next of kin. In moving what had previously been an offence tried by ecclesiastical courts into the secular ones, Henry may have intended it as a simple expression of political power along with other contemporary acts such as Submission of the Clergy Act 1533 (25 Hen. 8 c. 19) and one year before the Act of Supremacy 1534 (26 Hen. 8. c. 1). However Henry later used the law to execute monks and nuns (thanks to information his spies had gathered) and take their monastery lands—the same tactics had been used 200 years before by Philip IV of France against the Knights Templar.

In July 1540, Walter Hungerford, 1st Baron Hungerford of Heytesbury, was charged with treason for harbouring a known member of the Pilgrimage of Grace movement. He was also accused of buggery, as he was suspected of raping his own daughter. Hungerford was beheaded at Tower Hill, on 28 July 1540, the same day as Thomas Cromwell.

Nicholas Udall, a cleric, playwright, and Headmaster of Eton College, was the first to be charged with violation of the Act alone in 1541, for sexually abusing his pupils. In his case, the sentence was commuted to imprisonment and he was released in less than a year. He went on to become headmaster of Westminster School.

The act was repealed in 1553 on accession of the staunchly Catholic Queen Mary, who preferred such legal matters adjudicated in ecclesiastical courts.^[which?] However, it was re-enacted by Queen Elizabeth I in 1562, by the Sodomy Act 1562 (5 Eliz. 1. c. 17), "An act for the punishment of the vice of buggery". Although "homosexual prosecutions throughout the sixteenth century [were] sparse" and "fewer than a dozen prosecutions are recorded up through 1660 ... this may reflect inadequate research into the subject, and a scarcity of extant legal records." In 1631 Mervyn Tuchet, 2nd Earl of Castlehaven, was beheaded because of his rank. Numerous prosecutions that resulted in a sentence of hanging are recorded in the 18th and early 19th centuries.