Ottokar Nováček (Czech: Otakar Evžen Nováček, German: Ottokar Eugen Nováček, Hungarian: Nováček Ottokár Jenő, Serbian: Otokar Novaček / Отокар Новачек; May 13, 1866 – February 3, 1900) was an Austro-Hungarian violinist and composer of Czech descent and is perhaps best known for his work Perpetuum Mobile (Perpetual Motion), written in 1895.
Novacek was born at Weißkirchen (Serbian: Bela Crkva / Бела Црква), southern Austrian Empire (today Serbia). He studied successfully with his father Martin Joseph Nováček, with Jakob Dont in Vienna (1880–83), and with Henry Schradieck and Brodsky at the Leipzig Conservatory, where he won the Mendelssohn Prize in 1885. He played in the Leipzig Gewandhaus Orchestra and in the Brodsky Quartet, originally as second violin and later as viola. He subsequently immigrated to the USA, where he was a member of the Boston Symphony Orchestra under Arthur Nikisch (1891) and was appointed principal viola in the Damrosch Orchestra, New York (1892-3). He also played in the re-formed Brodsky Quartet.