Parsemain, 26, is a native of Le Francois, Martinique, and is among his home country's leading scorers in international play.
"Kevin is a technically clean striker with a nose for the goal," Sounders sporting director Chris Henderson said in a press release. "He is a proven goal scorer for Martinique and we expect that to translate in MLS. We are looking forward to seeing Kevin debut for the Rave Green soon."
The 5-foot-10, 165-pound Parsemain played for the Sounders in the preseason, and tied for the team lead with three goals in six appearances. A professional since 2004, he has also played for Le Mans B and Evian in France.
The Sounders play the Columbus Crew at CenturyLink Field at 7 p.m. Saturday.