Alexander Igorevich Grischuk (Russian: Александр Игоревич Грищук) (born October 31, 1983) is a Russian grandmaster.
In the FIDE World Chess Championship 2000 he made it to the semi finals, losing to Alexei Shirov. In the FIDE World Chess Championship 2004 he made it to the quarter finals, where he lost 3-1 to eventual champion Rustam Kasimdzhanov.
He finished in the top 10 in the 2005 FIDE World Cup, which qualified him for the 2007 Candidates Tournament in May-June 2007. He won his matches against Vladimir Malakhov (+2-0=3) and Sergei Rublevsky (tied at +1-1=4, winning the rapid playoff +2-0=1), to advance to the eight-player FIDE World Chess Championship 2007 tournament. In that tournament he scored 5.5 out of 14, placing last in the eight-player field.
Along with being a top-level professional, Grischuk is also known as one of the best blitz chess players in the world, having once held the record for highest rating achieved on the Internet Chess Club. In 2006 he won the World Blitz Championship in Rishon Lezion, Israel with 10.5 points out of 15 games, winning 10 games.
Grischuk was the champion of Linares 2009, winning on tie-break over Vassily Ivanchuk because he had more wins. In 2010, he finished second in Linares to Veselin Topalov.
Grischuk finished third in the FIDE Grand Prix 2008-2010, which qualified him as the first alternate for the Candidates Tournament of the World Chess Championship 2012 cycle. Upon the withdrawal of world #2 Magnus Carlsen from the candidates tournament, Grischuk was appointed to take his place.
Grischuk is married to the Ukrainian WGM Natalia Zhukova.