The 29-year-old arrived at The Emirates in June 2010 but failed to hold down a regular spot in Arsene Wenger's team and has been allowed to join the Gunners' Premier League rivals.
The Eagles' official website said: "Crystal Palace are delighted to confirm the signing of Morocco international striker Marouane Chamakh on a one-year deal.
"The former Arsenal forward has joined the Eagles on a permanent deal after completing a medical in SE25, and will wear the number 29 shirt."
The Moroccan, who has scored 17 goals in 63 appearances for his country, spent the second half of last season on loan at West Ham, where he made three appearances.
He is the third striker captured by Palace boss Ian Holloway this summer - joining veteran Kevin Phillips and Dwight Gayle.