Cowboys owner Jerry Jones had acknowledged last week that the 12th-year pro -- who has a recent history of complaining about his role, his contract or both -- likely would be playing elsewhere this fall.
But the writing already was on the wall by April's NFL draft, when the Cowboys focused on players who could help their pass rush, and Ellis, 33, did not participate in the team's May 21 organized team activities session.
By releasing him, the Cowboys save the $4.15 million he was scheduled to make in 2009. But they're also losing a team leader, and Ellis is the players' union team representative.
Ellis, the Cowboys' first-round pick in 1998, played in 162 games -- all with Dallas -- and started 156 of them.
Ellis complained in 2006 about moving from defensive end to linebacker, saying the Cowboys and former coach Bill Parcells were setting him up to fail in the new 3-4 defensive alignment.
After that turned out OK, Ellis squawked again a year later when the Cowboys drafted Anthony Spencer, another college defensive end they planned to move to outside linebacker.
Back then, Ellis said he was sure they were trying to replace him and demanded a new contract that showed the team's commitment. He got the new deal in 2007 and responded with his best season, a Pro Bowl year with a career-high 12½ sacks even though he missed the first three games to recover from a torn Achilles tendon. He was named the NFL Comeback Player of the Year in 2007.
Ellis finished his Cowboys career with 634 tackles, 36 tackles for losses, 197 quarterback pressures and 77 sacks.
Information from The Associated Press was used in this report.