West End theatre is mainstream professional theatre staged in the large theatres in and near the West End of London. Along with New York City's Broadway theatre, West End theatre represents the highest level of commercial theatre in the English-speaking world. Seeing a West End show is a common tourist activity in London. Famous screen actors, British and international alike, frequently appear on the London stage.

Theatre or theater is a collaborative form of performing art that uses live performers, usually actors or actresses, to present the experience of a real or imagined event before a live audience in a specific place, often a stage. The performers may communicate this experience to the audience through combinations of gesture, speech, song, music, and dance. It is the oldest form of drama, though live theatre has now been joined by modern recorded forms. Elements of art, such as painted scenery and stagecraft such as lighting are used to enhance the physicality, presence and immediacy of the experience. Places, normally buildings, where performances regularly take place are also called "theatres", as derived from the Ancient Greek θέατρον, itself from θεάομαι.