The France international took his case to world football's governing body after an independent tribunal under Premier League rules had already ruled the disputed 12-month extension binding, with FIFA confirming this week that the matter falls outside its jurisdiction.
Mateta signed for Palace from Mainz 05 in January 2021, initially on an 18-month loan, before completing a permanent four-and-a-half-year deal a year later that carried the option of a further 12 months.
The Eagles activated that extension in 2024, pushing the contract's expiry to June 2027. The 29-year-old has argued that final year should not stand, though neither the tribunal nor FIFA has accepted the challenge, and BBC Sport reports the deal remains binding.
Had Mateta succeeded, he would likely have been on course to become a free agent before his Palace contract's stated expiry next summer. Instead he remains tied to the club, with Crystal Palace previously setting a £35 million asking price when the striker pushed to leave in January.
A move to AC Milan collapsed at the medical stage after the Serie A club identified a knee issue that later required surgery.
Mateta has become one of the most productive forwards in Palace's history since his arrival, scoring 67 goals in south London and playing a central role in the club's FA Cup and Conference League triumphs under former manager Oliver Glasner.
He started the Eagles' Premier League opener at Everton on Saturday under new boss Pierre Sage, though he was substituted after 63 minutes of the 2-0 defeat.
The forward has also been linked with a move to Tottenham Hotspur this week, though his contract standoff with Palace is likely to complicate any deal before the transfer window closes. Talks over a new Palace contract were described as positive earlier this year before stalling, and Mateta is understood to be in no rush to commit his long-term future to Selhurst Park.