The exodus from the San Francisco 49ers continues.
Smith, 35, played seven seasons with the Cincinnati Bengals and seven with the 49ers. He was considered one of the hardest-working players on the 49ers and an on-field leader.
“Justin is the consummate professional whose impact on this organization can never be measured by statistics alone,” 49ers General Manager Trent Baalke said. “His durability, competitiveness, work ethic, strength and rare stamina helped set him apart over his 14-year career."
Selected fourth overall by the Bengals in 2001, Smith signed with the 49ers in 2008. He was named to the Pro Bowl five straight seasons starting in 2009 and earned the 49ers' most-valuable player award in 2008 and 2011.
Smith, who recorded 87 sacks and 613 tackles during his career, is the latest standout player to retire from the 49ers. Veteran linebacker Patrick Willis and promising rookie linebacker Chris Borland each made surprising retirement announcements earlier this year.