Lightly coat the inside of a 3-1/2- or 4-quart slow cooker with cooking spray. Place chicken pieces in the prepared cooker. Top with artichoke hearts and olives. Pour pasta sauce over artichokes and olives.
Cover and cook on low-heat setting for 6 to 7 hours or on high-heat setting for 3 to 3-1/2 hours. To serve, sprinkle each serving with feta cheese. Makes 6 servings.