Friederike Sophie Seyler (1738 – 22 November 1789; née Sparmann, formerly married Hensel) was a German actress, playwright and librettist. Alongside Friederike Caroline Neuber, she was widely considered Germany's greatest actress of the 18th century; Gotthold Ephraim Lessing described her in his Hamburg Dramaturgy as "incontestably one of the best actresses that German theatre has ever seen."
The granddaughter of the architect Matthäus Daniel Pöppelmann, she ran away from an abusive uncle under the threat of a forced marriage to join the theatre at the age of sixteen in 1754. She established herself as one of Germany's leading actresses in the 1760s and was acclaimed for her portrayal of passionate, majestic, tragic heroines. From 1767 she was professionally and personally associated with the theatre director Abel Seyler, whom she married in 1772, as the leading actress of the Hamburg National Theatre and later of the Seyler Theatre Company. With Seyler she led an itinerant life until her death, performing widely across the German-speaking realm. She also stayed for several periods at the Vienna Burgtheater between 1757 and 1772. She was associated with all the leading theatres of her era: Hamburg, Vienna, Weimar, Gotha and Mannheim.
