Jón Loftur Árnason (born 13 November 1960) is an Icelandic chess grandmaster, three-time national champion, and successful businessman.
Like fellow Scandinavians Simen Agdestein and Magnus Carlsen, Árnason in his youth was hailed as a potential world champion after a string of results. In 1976, while only 15, he finished equal first in an event for players under 21. The same year, he won an Icelandic open tournament with the score of 9.5/11. Just a year later, playing in a telex match for Iceland against England, he drew as Black against Jonathan Mestel, an established master. Also in 1977, at Cagnes-sur-Mer, he won the World Under-16 championship (ahead of other distinguished young talents, including Garry Kasparov), before becoming Icelandic champion on the first of three occasions (1977, 1982 and 1988). Shortly thereafter, he accepted an invitation to join the Botvinnik chess school. In 1979, FIDE awarded him the title of International Master.
In international competition, he took first at Husavik 1985, Plovdiv 1986 and Helsinki 1986 (shared). In 1986, FIDE awarded him the International Grandmaster title.
In individual encounters with some of the world's best players, he showed that he was always a very dangerous opponent. He defeated world championship contenders and super-grandmasters of the calibre of Short, Korchnoi, Shirov, Adams, Dreev, Vaganian and Larsen. He has also drawn former world champions Petrosian, Smyslov, Tal, Karpov, and Khalifman.
Representing the national Olympiad team between 1978 and 1994, he helped Iceland to very respectable 5th and 6th place finishes in 1986 and 1992 respectively. From 1982 onwards, he consistently turned in high scores in this arena.
Jón Loftur Árnason ceased playing competitively around 1995, in order to concentrate on his other passion, business and finance. He obtained a Degree in Finance and Accounting from the University of Iceland and embarked on a career that took him to Icelandic dot-com firm Oz Communications Inc., where he was appointed company Secretary and Treasurer. Perhaps due to his elevated position, the company showed an affinity with chess and in 2000, sponsored the prestigious rapid chess@iceland tournament, won by Kasparov ahead of Anand. Jón Loftur Árnason took part, but was by then short of top class practice and finished in last place. Since then, he has continued to play only in a minor capacity, mainly in local team tournaments.