Grzegorz Kosok (born 2 March 1986) is a Polish former professional volleyball player, a member of the Poland national team in 2011–2013, a participant at the Olympic Games London 2012, and the 2012 World League winner.

With the club from Rzeszów he achieved two gold (2012, 2013), silver (2014) and two bronze medals (2010, 2011) of the Polish Championship.

[1] First time, he was appointed to the Polish national team by Andrea Anastasi in 2011.

He won a bronze medal of the 2011 FIVB World League and the 2011 CEV European Championship.

[2] In November 2011 Poland won a silver medal of the 2011 FIVB World Cup and therefore qualified for the 2012 Olympic Games in London.