NK Marsonia is a Croatian football club based in the city of Slavonski Brod.

NK Marsonia last played in the top flight 1.HNL in 2004, finishing last and suffering relegation.

[3] On August 1, 2011, NK Marsonia merged with MV Croatia to form NK Marsonia 1909 which will compete in Croatian second division.

NK Marsonia will continue functioning as the new club's second team.

Some of Marsonia's notable former players include Mario Mandžukić,[4] Ivica Olić, Veldin Karić, Boris Živković and Josip Weber.