Theodor Lay was a nineteenth-century German operatic baritone who was particularly admired for his interpretations of the roles of Richard Wagner and Albert Lortzing.
He is best remembered today for portraying the role of Baal-Hanan in the world premiere of Karl Goldmark's Die Königin von Saba in 1875.
He appeared in his first featured opera role in the world premiere of Albert Lortzing's Rolands Knappen oder Das ersehnte Glück in 1849.
In 1856 he returned to Leipzig to portray the role of Peter the Great in Lortzing's Zar und Zimmermann.
He notably portrayed the role of Sixtus Beckmesser in the Viennese premiere of Richard Wagner's Die Meistersinger von Nürnberg in 1870.