The Orchestra of the Age of Enlightenment (OAE) is a British period instrument orchestra. The OAE is a resident orchestra of the Southbank Centre, London, associate orchestra at Glyndebourne Festival Opera Artistic Associate at Kings Place, and has its headquarters at Acland Burghley School. The leadership is rotated between four musicians: Matthew Truscott, Kati Debretzeni, Huw Daniel and Margaret Faultless.

A group of period instrumentalist players formed the OAE as a self-governing ensemble in 1986, and took its name from the historical period in the late 18th century where the core of its repertoire is based. The OAE does not have a principal conductor, but chooses conductors individually. The current Principal Artists are Sir Simon Rattle, Vladimir Jurowski, Iván Fischer, John Butt, Sir Mark Elder and András Schiff. Sir Roger Norrington and William Christie are Emeritus Conductors, as were the late Frans Brüggen and Sir Charles Mackerras. Other conductors to have worked with the OAE at its invitation include Marin Alsop, Anu Tali, Yannick Nézet-Séguin, Sian Edwards, Edward Gardner, Suzi Digby, Robin Ticciati, Joanna Tomlinson, Philippe Herreweghe, Gustav Leonhardt, René Jacobs, Harry Bicket, Christopher Hogwood, Sigiswald Kuijken, Ivor Bolton, Monica Huggett, and Bruno Weil.

Sir Martin Smith was instrumental in establishing the OAE, securing crucial private funding for its inaugural work and serving on the Board for many years. He is Life President of the orchestra.