Østbye is a surname. Notable people with the surname include:
Adolf Østbye (1868–1907), Norwegian revue artist and barber Gudbrand Østbye (1885–1972), Norwegian army officer and historian Peter Østbye (1855–1943), Norwegian philologist and academic administrator Rolf Østbye (1898–1979), Norwegian businessman Sverre Østbye (1889–1984), Norwegian Nordic skier