Guðmundur Sigurjónsson is an Icelandic chess grandmaster. He was born on July 25, 1947, in the village of Bolungarvík, in the country's Westfjords region.
Sigurjónsson was a prominent chess player during the 1960s and 1970s. He first achieved international ranking at the 1966 World Student Team Chess Championship in Örebro, Sweden, where he earned the title of International Master. He became an International Grandmaster in 1975.
Sigurjónsson won the Icelandic Chess Championship three times. His victories occurred in 1965, 1968, and in 1972. He represented Iceland at eleven Chess Olympiads, playing on the team that placed fourth in the 1974 and 1982 games.
In addition to his performance in competition, Sigurjónsson has contributed to chess in Iceland as an instructor and organizer. He was a founder of the Icelandic Chess Federation’s academy, and he served as President of the organization for a few years. He also worked as Chairman of the Icelandic Sports Association's chess division, and has written about the game for various publications.
After his competitive career, Sigurjónsson has continued to maintain an active role in the chess community. He organized the Reykjavík Open and the Match of the Century, an exhibition featuring prominent players from the 1972 World Chess Championship, including World Champion Bobby Fischer, whom Sigurjónsson befriended and assisted during Fischer's residency in Iceland.