Igor Vasilyevich Ivanov (January 8, 1947 – November 17, 2005) was a Russian-born chess grandmaster who defected from the Soviet Union to Canada in 1980.

Ivanov did qualify for the 1975 Soviet Championship First League; this event, with several grandmasters in the field, was still one stage below the top level at that time.

[4] He tied for first place with the 15-year-old prodigy, Garry Kasparov, at the 64-player Soviet Championship Otborochnii (qualifying tournament) held at Daugavpils, Latvia, in 1978.

Ivanov first became known internationally later in 1979, when he upset World Champion Anatoly Karpov in a superb game at the Spartakiad of the Peoples of the USSR team tournament.

On what was supposed to have been a direct flight home to Moscow, the airplane, a Czechoslovak airliner, had to make an emergency stop to refuel in Gander, Newfoundland.

His first significant tournament win in Canada was the 1980 Quebec Open Championship in Montreal, where he made an undefeated 7/8, to finish half a point ahead of Kevin Spraggett, whom he defeated in their head-to-head game.

[2] At the 1982 Toluca Interzonal, Ivanov narrowly missed a grandmaster norm as well as advancing as a Candidate, finishing in a 4th-place tie with Lev Polugaevsky, Artur Yusupov, and Yasser Seirawan.

[9] Later that year, he represented Canada on top board at the Lucerne Chess Olympiad, where he defeated Jan Timman and Tony Miles.

"[2] Ivanov moved in the 1980s to the United States (although he continued to visit Canada), where he participated in the Grand Prix tournaments (also known as the "Church's Chicken Circuit") to earn a living.

Ivanov's consumption of alcohol, which had always been heavy, grew increasingly out of control; there were reports of him playing at the US Chess Championship while intoxicated.

The Professional Players' Health and Benefit Fund of the United States Chess Federation gave him financial support for his chemotherapy treatments.