Haakon Ragnvald Olsen Sund (5 April 1873 – 31 December 1965) was a Norwegian judge and prosecutor. He took the cand.jur. degree in 1895, and became police chief in Bodø in 1904. In 1913 he was promoted to Public Prosecutor (Norwegian: statsadvokat) in Nordland. He then advanced further, to district stipendiary magistrate in Midhordland District Court in 1919, presiding judge in Frostating and Gulating Court of Appeal in 1926, and in 1929 he was appointed as the Norwegian Director of Public Prosecutions.