Jón Loftur Árnason is an Icelandic chess player known for achieving the title of chess Grandmaster in 1986. He was born on 13 November 1958 in Reykjavík, Iceland. He won the Nordic Chess Championship in 2000 and was Icelandic Chess Champion several times.
Over the course of his career, Árnason represented Iceland in numerous Chess Olympiads, with his first participation coming in 1978. He achieved outstanding results, including getting the highest percentage score on board four.
In the FIDE (World Chess Federation) World Chess Championship 1999, he reached the second round, after beating Pavel Blatny in the first but losing to Michal Krasenkow in the second. In 1991, Árnason briefly retired from chess to work in a bank. However, he returned to chess in the late 90s and continues to compete intermittently.
Árnason also significantly contributed to chess pedagogy, writing multiple chess books and column articles. He's a part of the "New in Chess" yearbook team, contributing games and analysis for each edition.
Árnason is known as one of the key figures in Icelandic chess.