The Steelers have hired Porter as a defensive assistant, returning him to the city where he earned three Pro Bowl selections as an outside linebacker as well as a Super Bowl ring.
"We are excited about having Joey back with the Steelers family," coach Mike Tomlin said Tuesday in a statement. "Joey spent a number of years with Pittsburgh as a player, and now he's back to assist the coaching staff. We look forward to his efforts and contributions."
Porter spent last season as an assistant coach at Colorado State, where he also completed his degree in sociology. He interned with the Steelers during training camp prior to returning to his alma mater.
He played for the Steelers from 1999 to 2006 and is fifth on the team's all-time sacks list with 60. His sheer force of personality and ability to get after the quarterback helped propel the Steelers to the four postseason wins they needed in 2005 to claim a fifth Super Bowl title.
The Steelers became the first team to win the Super Bowl as a No. 6 seed in the playoffs.
Pittsburgh released Porter in 2007, less than two months after Tomlin was hired as coach, saving $6 million and allowing James Harrison to take over at right outside linebacker.
Porter had been one of the most popular players among his teammates as well as the most outspoken one before the Steelers parted ways with him.
He signed a five-year, $32 million contract with the Miami Dolphins, and in 2008, he recorded a career-high 17.5 sacks and made his fourth Pro Bowl. He played three seasons with Miami and two with the Arizona Cardinals.
Pittsburgh signed Porter to a one-day contract shortly after he announced his retirement in July 2012 so he could officially retire as a Steeler.