The Ghana forward’s previous contract was set to expire at the end of this month, and there were reports of clubs interested in acquiring his services, but he chose to stay with Crystal Palace.
The 30-year-old joined on loan from Swansea in 2018 and signed a three-year contract the following year.
Crystal Palace also announced one-year extensions for James McArthur, James Tomkins, and Nathaniel Clyne.
The quartet have made a combined 677 appearances for Palace, with Tomkins contributing 124, Ayew 133 and right-back Clyne 171.
“It remains of pivotal importance to get the right balance of youth and experience in any Premier League squad,” said Palace chairman Steve Parish.
“I’m delighted that we’ve been able to ensure that these long-standing and experienced players in Jordan, Nathaniel, James and James remain with us for the upcoming campaign.
“Each of them played an enormous role in the progress we’ve all enjoyed in the last year, and we very much expect similar contributions for the season ahead.”
Ayew had three goals and three assists in 31 Premier League games last season.