Grzegorz Kosok (born 2 March 1986) is a Polish former volleyball player, member of the Poland men's national volleyball team in 2011–2013, participant of the Olympic Games (London 2012), gold medallist of the 2012 World League, bronze medallist of the 2011 European Championship and 2011 World League, three–time Polish Champion (2012, 2013, 2021).