Alexander Onischuk was born in Sevastopol and spent the first half of his life in Ukraine, representing the country at three Chess Olympiads.

After moving to the USA in 2001, he competed in the U.S. Championship, winning in 2006, finishing 2nd in 2007, 2008, and 2017, and placing 3rd four times. He also represented the U.S. in six Chess Olympiads and seven World Team Chess Championships. These achievements earned him induction into the U.S. Chess Hall of Fame in 2018.

Onischuk is married to GM Natalia Zhukova, making them the only married couple competing in parallel in the Open and Women’s World Rapid Championship in New York.