According to ESPN's Chris Mortensen, the pick is a fifth-rounder.
Peters is in the fifth and final season of his rookie contract. The Rams acquired the former first-rounder from the Kansas City Chiefs before the 2018 season. In 22 regular-season games in L.A., Peters intercepted five passes, returning two for touchdowns. He made the Pro Bowl in 2015 and '16 with the Chiefs.
The trade also comes a day after the Rams placed their other starting cornerback, Aqib Talib, on injured reserve with a rib injury.
The Ravens' current plan is to work Peters into practice on Thursday and Friday and for him to play Sunday against Seattle, a source told ESPN's Josina Anderson. The Ravens are expecting Peters to arrive in Baltimore late afternoon/early evening Wednesday after taking care of some personal business.
Peters will get a chance to play against the Rams in Week 12 as Los Angeles will host the Ravens in a Monday night game.
Maurice Canady and Anthony Averett have struggled as starting cornerbacks. Quarterbacks have targeted them because they're throwing away from Marlon Humphrey, who has been playing at a Pro Bowl level.
Young began the season as Baltimore's weakside linebacker but fell out of favor after misplaying runs and having lapses in coverage. He was a healthy scratch in Week 5.
The second-year pro from UCLA started six games for the Ravens, with two forced fumbles and a fumble recovery.
The Ravens were able to give up the draft pick because they received a fifth-rounder from the Vikings this summer for kicker Kaare Vedvik.
Also on Tuesday, a day after Rams coach Sean McVay said the team would look to outside options to build depth on the offensive line, the Rams traded for Cleveland Browns lineman Austin Corbett, the team announced.
The Rams sent a 2021 draft pick to Cleveland in exchange for Corbett, who was selected in the second round of the 2018 draft from Nevada. Corbett appeared in 14 games for the Browns.
The Rams were in need of depth on their offensive line after left guard Joe Noteboom suffered a torn ACL and MCL in a Week 6 loss to the San Francisco 49ers. Noteboom will undergo season-ending surgery.
ESPN's Jamison Hensley contributed to this report.