BBC Sport journalist David Ornstein reports Ayew will undergo a medical with the Eagles today before becoming the fourth addition to Roy Hodgson's squad this summer.
Palace had previously been in talks to sign Ayew permanently in a part exchange deal with Jairo Riedewald, but the Dutchman refused to sign for the Swans.
Crystal Palace have finalised deal to sign Swansea forward Jordan Ayew on season-long loan, medical today. Takes Loftus-Cheek role but also option up front. No more #CPFC arrivals expected but exits are with offers on table for likes of Puncheon & Riedewald (not going to #Swans)— David Ornstein (@bbcsport_david) August 9, 2018
Riedewald is one of two Palace players who could leave Selhurst Park on deadline day, with Ornstein claiming that offers are on the table for him and Jason Puncheon.
Ayew can be a replacement for Ruben Loftus-Cheek, who was a key player for Hodgson's team last season but has not renewed his loan deal from Chelsea.
He can also be deployed as a striker. He scored 11 goals for Swansea last season but couldn't prevent them from being relegated to the Championship.
Swansea manager Graham Potter wanted Ayew out of the club after he refused to train with the squad earlier this week in an attempt to force a move to the Premier League.
"There's no further news on Jordan - he's just not been here," Potter told BBC Sport Wales.
"That tells you that he's not part of what we're trying to do, by his own actions."
Ornstein says that Ayew will be the only player to arrive at Palace on deadline day.