The Seyler Theatre Company, also known as the Seyler Company, was a theatrical company founded in 1769 by Abel Seyler, a Hamburg businessman originally from Switzerland who became "the leading patron of German theatre" in his lifetime. It was largely a continuation of the Hamburgische Entreprise, whose dramaturge was Gotthold Ephraim Lessing and whose main owner was Seyler. The Seyler theatrical company became one of the most famous theatrical companies of Europe in the 18th century, attracting some of Germany's leading actors, playwrights and composers. It originally comprised around 60 members, including an orchestra, a ballet, house dramatists and set designers. Between 1777 and 1778 Seyler employed some 230 actors, singers and musicians. The company was originally contracted by the Hanoverian court with performing at Hanover and other cities of the kingdom. The company would eventually perform all across Germany, and performed for three years at the Weimar Schlosstheater, invited by Duchess Anna Amalia of Brunswick-Wolfenbüttel. When Anna Amalia succeeded in engaging the Seyler Company, this was "an extremely fortunate coup. The Seyler Company was the best theatre company in Germany at that time." The company had an important role in the development of German opera in the late 18th century.

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.