Celek helped the Eagles win Super Bowl LII during the 2017 season; he subsequently retired that offseason.

[1] Celek played college football for the Cincinnati Bearcats, the first year under head coach Rick Minter and the following three seasons under Mark Dantonio.

He won the UC Claude Rost Award (Most Valuable Player) and was a second-team All-Big East Conference selection.

[7] Celek became the starting tight end for the Eagles after L. J. Smith departed via free agency to the Baltimore Ravens in 2009.

[8] After scoring a touchdown in a week 9 game at home against the Dallas Cowboys, Celek was penalized for excessive celebration after teammate Jason Avant lifted his leg in order to impersonate the mascot for Captain Morgan rum.

He was one of three Eagle offensive players to start all 16 games, along with right tackle Todd Herremans and rookie center Jason Kelce.

Going into the 2014 season, his eighth in the NFL, Celek stood second in Eagles team history in three tight end categories—all behind career leader Pete Retzlaff—in receiving yards (4,050), receptions (322), and touchdowns (26).

Celek finished the season with 32 receptions for 340 yards and 1 touchdown, which was less than half of teammate Zach Ertz's total.

However, in a Week 4 divisional matchup against the Redskins, he scored his first touchdown of the season on a 10-yard catch and run from new quarterback Sam Bradford.

Celek did, however, make a crucial block on Dallas' defensive end Greg Hardy in overtime that allowed Bradford to throw the game-winning touchdown.

[18] On February 7, 2020, Celek was hired as a personnel consultant in the Eagles' football operations department, alongside former teammate Darren Sproles.