Ivan Mršić (born August 1, 1949), also known as John Mrsic and Big J, is a Yugoslav retired footballer.

He was picked up by bigger club FK Borac Banja Luka the next season.

He turned down an offer from Croatian Giants HNK Hajduk Split and went on to play with many Yugoslav clubs including three first division clubs NK Olimpija Ljubljana, FK Radnički Kragujevac, and Yugoslav powerhouse FK Partizan although only playing two matches, both friendly.

[4] In 1981, Mršić signed with the Cleveland Force of the Major Indoor Soccer League.

[5][6][7][8][9][10][11][12][13] His son, Simon Mrsic, born 1991, is also a footballer, and has played with San Jose Earthquakes reserve team and of NK Osijek, FK Rudar Prijedor and OFK Bačka.