The Worshipful Company of Gunmakers, incorporating the London Proof House, is one of the 111 livery companies of the City of London.

A livery company is a type of guild or professional association that originated in medieval times in London, England. Livery companies comprise London's ancient and modern trade associations and guilds, almost all of which are styled the "Worshipful Company of" their respective craft, trade or profession. There are 111 livery companies in total. They play a significant part in the life of the City, not least by providing charitable-giving and networking opportunities. Liverymen retain voting rights for the senior civic offices, such as the Lord Mayor, Sheriffs and Common Council of the City Corporation, London's ancient municipal authority with extensive local government powers.