The 27-year-old, who will add valuable attacking options to cover the loss of Bruno Fornaroli to start the A-League season, joins City from Polish top division club, KS Cracovia, where he made 146 appearances, scoring 24 goals.
He also represented Poland’s under-19, under-20 and under-21 teams.
New City manager Warren Joyce said he is thrilled to secure the experienced midfielder.
“Marcin is an imaginative midfield player with high-level experience both in the top domestic league in Poland, and with the Polish national team,” Joyce said.
“He arrives at an important time for the team as we finalise our pre-season and prepare for our first A-League match, and I have no doubt the fans will be excited to see him play for the first time.”
Melbourne City host Brisbane Roar on October 6 in the opening game of the season.