The 21-year-old, who can play as both a full-back and winger, has made 16 appearances for his country.
"I'm happy to be here, I'm excited, and I can't wait to start," said Khalaili.
"I've followed the Premier League - it's a new challenge for me - and I've followed Crystal Palace for a long time. I'm happy to be here."
Khalaili becomes Palace's fifth signing of the summer transfer window, with Oscar Mingueza, Takehiro Tomiyasu, Dwight McNeil and Evann Guessand all having arrived at Selhurst Park.
"We are very excited to have completed this signing and we are delighted that Anan has chosen to continue his journey with Crystal Palace," said Palace chairman Steve Parrish.