Vilmos (Willi, Willy or Wilhelm) Thern (22 June 1847 – 7 April 1911) and Lajos (Louis) Thern (18 December 1848 – 12 March 1920) were Hungarian pianists and teachers. They were the sons of the composer and conductor Károly Thern. Their repertoire included works by Franz Liszt, who often attended their concerts and even played with them, as well as Bach, Mozart and Beethoven. They were also prolific arrangers for piano 4-hands, including: Sergei Bortkiewicz's Russian Dance, Op. 18 for piano duet was dedicated to Louis Thern.