Knudtzon is a surname. Notable people with the surname include:
Birger Knudtzon (born 1936), retired Norwegian rowerBroder Knudtzon (1788–1864), Norwegian merchant, politician and benefactorErling Knudtzon (born 1988), Norwegian football midfielderHans Carl Knudtzon (1751–1823), Norwegian merchant, ship-owner and politicianJørgen Alexander Knudtzon (1854–1917), Norwegian linguist and historianJørgen von Cappelen Knudtzon (1784–1854), Norwegian businessman and patron of the artsLeif Knudtzon (1895–1925), Norwegian modern pentathleteNic Knudtzon (1922–2013), Norwegian telecommunications engineerAndrew Johnson Knudtzon (c.1880s), fish business owner (cod processing), Hull and grandfather of aviator Amy Johnson