Through the end of the season, Turkish international Cenk jumped ship Friday from one English team to another.
Crystal Palace signed Tosun on loan from Everton for a half-season deal.
"We're delighted to have secured Cenk's services for the remainder of this season," Crystal Palace Chairman Steve Parish said on the club's website.
"We've enjoyed a great first half of the campaign and Cenk's arrival will bolster our squad as we push for a top-half Premier League finish.
"Cenk has a proven record as a goalscorer and we've admired him for some time, so I'm very pleased to welcome him to Crystal Palace."
The 28-year-old forward joined Everton from Turkish club Besiktas in January 2018 and scored 10 goals in 51 matches for Everton.
In addition to his club career, he featured for Turkey in the EURO 2016 and finished as top scorer -- five goals -- in the country's qualification for EURO 2020 European Football Championship.
To date Tosun helped Turkey with 16 goals in 42 games.
