On Wednesday, the Steelers said they plan on releasing wide receiver Hines Ward after 14 seasons with the team.
The Pittsburgh Tribune-Review reported Smith's release on Thursday.
"Bittersweet day today. Celebrating the great career of a great person today aaron smith who will be released by steelers today," said Peter Schaffer, Smith's agent, on his Twitter page.
Smith played 13 seasons for the Steelers, who drafted him in the fourth round of the 1999 draft. He played in every Steelers game at left defensive end from 2000 through 2006.
The 35-year-old Smith had established himself as one of the best defensive ends in the league before injuries conspired against him. The Northern Colorado product has been limited to a combined 15 games over the last three seasons.
In 160 career games with the Steelers, Smith had 408 tackles, 44 sacks and one interception. He won two Super Bowl titles with Pittsburgh.
Smith had been set to make $4.5 million this season.