Idrettsforeningen Ørnulf is a Norwegian sports club from Oslo. It has sections for amateur boxing and floorball.

The club was founded in 1893, and was a founding member of the Norwegian Wrestling Federation.^[1] It formerly had sections for track and field and amateur wrestling.

Well-known boxers include Hjalmar Nygaard (1920 Olympian),^[2] Edgar Christensen (1924 Olympian),^[3] Arthur Olsen (1928 Olympian),^[4] Asbjørn Berg-Hansen (1936 Olympian),^[5] Simen Auseth (1984 Olympian)^[6] and Thomas Hansvoll (later professional).^[1]

Well-known wrestlers include Karl Norbeck, Kjell Steen-Nilsen^[1] and Thorvald Olsen (1912 Olympian),^[7] Alfred Gundersen (1912 Olympian),^[8] Ansgar Løvold (1912 Olympian),^[9] Thorbjørn Frydenlund (1912 Olympian),^[10] Richard Frydenlund (1912 and 1920 Olympian),^[11] Bjørn Cook (1948 Olympian),^[12] Egil Solsvik (1948 Olympian),^[13] Bjørn Larsson (1952 Olympian).^[14]

Well-known athletes include Per Oscar Andersen,^[1] Carl Albert Andersen (1900 Olympian in athletics),^[15] Oscar Guttormsen (1906 and 1908 Olympian),^[16] Carl Alfred Pedersen (1906 Olympian in athletics),^[17] Fritz Skullerud (1906 Olympian),^[18] Halfdan Bjølgerud (1906 Olympian),^[19] Rolf Stenersen (1920 Olympian),^[20] Helge Løvland (1920 Olympic champion),^[21] Hans Gundhus (1924 Olympian),^[22] John Johansen (1908 Olympian, but not for Ørnulf) and Bjarne Guldager (1920 Olympian, but not for Ørnulf).