Hilliard takes over for interim receivers coach Ray Sherman, who came out of retirement to replace Darryl Drake after Drake's death during last year's training camp.
Hilliard previously served as the Washington Redskins' wide receivers coach from 2014 to 2019, his second stint with the franchise in that role after holding the position in 2012. He also worked as the wideouts coach for the Buffalo Bills in 2013 and as the assistant receivers coach for the Miami Dolphins in 2011.
Before his coaching career, Hilliard was an All-American receiver at the University of Florida and was selected by the New York Giants in the first round (No. 7 overall) of the 1997 NFL Draft.
Hilliard played eight seasons with the Giants (1997-2004) before spending his final four seasons with the Tampa Bay Buccaneers (2005-08). In 161 career games, he recorded 546 receptions for 6,397 yards and 35 touchdowns.
Hilliard became the second off-season hire for the Steelers, who previously added Matt Canada as the team's quarterbacks coach.