The 46-year-old Ryan replaces the fired Eric Mangini. Ryan takes over a team that started last season 8-3 but missed the playoffs with quarterback Brett Favre after losing four of its last five games.
Ryan is expected to be formally introduced at a news conference Wednesday at the Jets' facility in Florham Park, N.J.
"I'm very much looking forward to meeting Coach Ryan," wide receiver Chansi Stuckey told The Associated Press in an e-mail. "His reputation precedes him by the success that Baltimore has had, and I'm very excited to get started."
The Ravens' defensive coordinator the last four seasons is the son of former NFL coach Buddy Ryan and twin brother of Cleveland defensive coordinator Rob Ryan.
Ryan's defense, which helped Baltimore to the AFC championship game, has been ranked in the top six in total yardage allowed the last four seasons, including second overall this season while leading the NFL with 34 takeaways.
This will be the first head coaching job for Ryan, who is said to be well liked among his players because of his straightforward, no-nonsense style.
It became apparent Ryan was at the top of the Jets' list of candidates when several other teams filled their coaching vacancies and New York's remained open. The Jets needed Baltimore's season to end - which happened Sunday with a 23-14 loss at Pittsburgh - before offering him the job.
Ryan, who also interviewed for the St. Louis Rams job that went to Giants defensive coordinator Steve Spagnuolo, impressed the Jets when he met with team officials earlier this month.
The Jets interviewed at least five other candidates, including offensive coordinator Brian Schottenheimer, assistant head coach/offensive line coach Bill Callahan, Arizona assistant head coach/offensive line coach Russ Grimm, Indianapolis defensive coordinator Ron Meeks and fired Boston College coach Jeff Jagodzinski.
Whether Ryan will have Favre on his roster this season is unclear. The 39-year-old quarterback recently said he would take several weeks before deciding whether to return.
Favre said he was disappointed with how his first season ended with the Jets, throwing nine interceptions in New York's last five games. He also tore a biceps tendon in his right arm that won't require surgery.
Owner Woody Johnson and general manager Mike Tannenbaum have said they want Favre back, but added the new coach would have significant input on the final decision.
Nicknamed "The Mad Scientist" for his aggressive and unpredictable game plans, Ryan prefers to run a 3-4 defensive scheme, which the Jets already have in place. New York spent big money last offseason acquiring players that excel in the 3-4, including nose tackle Kris Jenkins and linebacker Calvin Pace.
That might have given Ryan a slight edge over Spagnuolo, who prefers a 4-3 scheme.
Ryan inherits a defense that had an impressive start with 29 sacks in its first eight games but just 12 in the last half of the season. The secondary also might need a makeover, ranking 29th overall against the pass despite Pro Bowl cornerback Darrelle Revis and playmaking safety Kerry Rhodes.
Although the Jets scored 405 points, the third-highest total in franchise history, the offense still has glaring needs. Other than determining who's at quarterback - whether it's Favre, Kellen Clemens, Brett Ratliff or a veteran free agent such as Kerry Collins or Byron Leftwich - the Jets need a tall, speedy receiver to complement Jerricho Cotchery and Laveranues Coles.
Ryan, who spent 10 seasons with the Ravens, was the only remaining defensive assistant from Baltimore's 2000 Super Bowl team. He spent six years as the Ravens' defensive line coach before being promoted to coordinator.
The Ravens fired coach Brian Billick and his entire staff, including Ryan, after the 2007 season. Ryan interviewed for the job that eventually went to John Harbaugh, who rehired Ryan and added the title of assistant head coach.
After a few stops as an assistant at the college level, Ryan spent two years under his father as a defensive assistant with the Arizona Cardinals. He then became the defensive coordinator at the University of Cincinnati before taking the same job at Oklahoma. Ryan joined the Ravens before the 1999 season, working his way up to defensive coordinator.
AP Sports Writer Larry Lage in Detroit contributed to this report.
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