The Union Chapel, also known as the Union Street Chapel, Elim Free Church, Four Square Gospel Tabernacle or Elim Tabernacle of the Four Square Gospel, is a former chapel in the centre of Brighton, a constituent part of the city of Brighton and Hove, England. After three centuries of religious use by various congregations, the chapel—which had been Brighton's first Nonconformist place of worship—passed into secular use in 1988 when it was converted into a pub. It was redesigned in 1825, at the height of Brighton's Georgian building boom, by at least one of the members of the Wilds–Busby architectural partnership, Brighton's pre-eminent designers and builders of the era, but may retain some 17th-century parts. It has been listed at Grade II in view of its architectural importance.

Amon Wilds was an English architect and builder. He formed an architectural partnership with his son Amon Henry Wilds in 1806 and started working in the fashionable and growing seaside resort of Brighton, on the East Sussex coast, in 1815. After 1822, when the father-and-son partnership met and joined up with Charles Busby, they were commissioned—separately or jointly—to design a wide range of buildings in the town, which was experiencing an unprecedented demand for residential development and other facilities. Wilds senior also carried out much work on his own, but the description "Wilds and Busby" was often used on designs, making individual attribution difficult. Wilds senior and his partners are remembered most for his work in post-Regency Brighton, where most of their houses, churches and hotels built in a bold Regency style remain—in particular, the distinctive and visionary Kemp Town and Brunswick estates on the edges of Brighton, whose constituent parts are Grade I listed buildings.