He began his career at Leicester - making 150 appearances for the club, scoring 15 goals - and had a loan spell at Brentford during 2010-11. West Brom boss Tony Pulis had been interested in Schlupp, who joins a Palace side 17th in the Premier League. The Eagles, one point above the relegation zone, visit West Ham on Saturday, a game Schlupp is available for. Allardyce said: "He will bring strength and experience to the defence and will be a major asset for the club."
Sunderland manager David Moyes had earlier confirmed the club had rejected a bid from Palace for Netherlands defender Patrick van Aanholt.