The linebacker, who retired after 17 seasons, will appear on "Monday Night Countdown," "Sunday NFL Countdown" and "SportsCenter."
He also will travel to the site of each week's "Monday Night Football" game, where he will offer analysis for ESPN's shows and have a weekly segment on ESPN Radio's "Mike and Mike in the Morning."
"ESPN is such a big part of how fans watch and experience sports, especially the NFL, so I'm excited to join their team," Lewis said in a statement. "I'm ready to bring the same level of passion to this next phase of my life as I brought to the field during my years as a player. I can't wait to work with my new teammates, many of whom I've already known for years."
Lewis helped the Ravens win two Super Bowl titles during his career and was selected to 12 Pro Bowls, fifth on the all-time list and most by a linebacker. He was named The Associated Press' Defensive Player of the Year in 2000 and 2003 and retired as the Ravens' franchise leader in several categories, including tackles (2,643), fumble recoveries (31) and games played (228).
"Ray is a tremendous addition to our NFL roster and he will have an immediate impact on our coverage," said John Wildhack, ESPN executive vice president, production. "One of the most accomplished players in NFL history, fans will be drawn to his knowledge, experience and, of course, the passion he always exudes for the game."