Károly Balzsay (born 23 July 1979) is a Hungarian former professional boxer who competed from 2004 to 2012.

Amateur record: W231-L27-D2 (72KO's) He made his professional debut on September 11, 2004 in the Kisstadion of Budapest against Milojko Pivljanin of Serbia and Montenegro.

In January, 2009 he won the WBO super middleweight title from Denis Inkin and became the third Hungarian World Champion of Universum Box-Promotion after István Kovács and Zsolt Erdei.

In August 2009 he lost the title in his second defense against Robert Stieglitz by an 11th round TKO.

[1] In 2011, Balzsay defeated Stanyslav Kashtanov to win the vacant WBA (Regular) super-middleweight title, he made one defence against Dimitri Sartison.