The centre-half, who signed on a short-term deal in August, is now committed to the club until the end of the following campaign.
Delaney has played a key role in Palace's rise up the Championship table, starting all 14 league games since he arrived from Ipswich.
The Londoners, who had lost all three of their previous Championship fixtures, have not been beaten since and now sit two points clear at the top.


 





