Gunnar Pétursson Thorsteinsson (26 June 1894 – 5 March 1921) was an Icelandic footballer.
[1] Gunnar was the son of the entrepreneur Pétur J. Thorsteinsson and Ásthildur Guðmundsdóttir.
[1] Gunnar joined Fram in 1913, quickly becoming one of their best players.
[1][2] He was the Icelandic tournaments top goal scorer during the 1917 season.
[3] In the fall of 1919, Gunnar fell ill with pulmonary tuberculosis.