• The Honourable Society of Gray's Inn, commonly known as Gray's Inn, is one of the four Inns of Court (professional associations for barristers and judges) in London. To be called to the Bar and practise as a barrister in England and Wales, an individual must belong to one of these Inns. The Inn is both a professional body and a provider of office accommodation (chambers) for many barristers. It is ruled by a governing council called "Pension", made up of the Masters of the Bench (or "Benchers"), and led by the Treasurer, who is elected to serve a one-year term.

Gray's Inn and the other three Inns of Court remain the only bodies legally allowed to call a barrister to the Bar, allowing him or her to practise in England and Wales. Although the Inn was previously a disciplinary and teaching body, these functions are now shared between the four Inns, with the Bar Standards Board (a division of the General Council of the Bar) acting as a disciplinary body and the Inns of Court and Bar Educational Trust providing education. The Inn remains a collegiate self-governing, unincorporated association of its members, providing within its precincts library, dining, residential and office accommodation (chambers), along with a chapel.

The Inn is run by Pension, its ultimate governing body. The name is peculiar to Gray's Inn—at Lincoln's Inn the governing body is called the Council, and at the Inner and Middle Temples it is called the Parliament. The name was used for the governing bodies of three of the Inns of Chancery—Barnard's Inn, Clement's Inn and New Inn.[58] In Gray's Inn the Readers, when they existed, were required to attend Pension meetings, and other barristers were at one point welcome to, although only the Readers would be allowed to talk. Pension at Gray's Inn is made up of the Masters of the Bench, and the Inn as a whole is headed by the Treasurer, a senior Bencher. The Treasurer has always been elected, and since 1744 the office has rotated between individuals, with a term of one year.

Having existed for over 600 years, Gray's Inn has a long list of notable members and honorary members. Even as the smallest of the Inns of Court it has had members who have been particularly noted lawyers and judges, such as Francis Bacon,[63] Baron Slynn, Lord Bingham of Cornhill, Lord Hoffmann and others. Outside the Bar and judiciary of England and Wales, members have included the clergy (including five Archbishops of Canterbury),[108] industrialists like John Wynne, astronomers such as John Lee, media figures, like Huw Thomas,[109] and members of the Bar and judiciary of other nations, such as Yang Ti-liang (former Chief Justice of the Supreme Court of Hong Kong) and Aitzaz Ahsan (former president of the Supreme Court Bar Association of Pakistan).