That actor is Ryan Eggold, and he's been delivering solid turns in notable film and television projects for the better part of the past two decades. "The Blacklist" is just the tip of the iceberg, too, with Eggold having appeared in series like "Veronica Mars," and "Entourage," before scoring his headlining turn as Dr. Max Goodwin in NBC's recently-wrapped medical drama "New Amsterdam." On the big screen, the actor can be seen in lauded indies such as "The Disappearance of Eleanor Rigby" films, "Lovesong," and "Never Rarely Sometimes Always." He also wrote and directed the 2017 indie "Literally, Right Befroe Aaron," and appeared in Spike Lee's Oscar-winning historical drama "BlaKkKlansman" in a role even he claimed was difficult to play, telling Today that, "It takes you a moment to sort of get comfortable going to that ... ugly place."
And yes, one of the bigger breaks of Ryan Eggold's early career came on The CW's teen melodrama "90210," which was a pseudo revival of the iconic 90s TV show "Beverly Hills, 902010." Though said revival focused largely on a new class of kiddos at West Beverly High School, it also returned a few original cast members including Jennie Garth and Shannen Doherty. As for Ryan Eggold, he portrayed West Beverly's soulful, but oft-misguided English Lit teacher Ryan Matthews, who has an on-again, off-again thing with Garth's Kelly Taylor during his three-season run on the show.
All in, Ryan Eggold is credited for 68-episodes of "90201," though many of those are listed on IMDb as "credit only." Either way, Eggold has clearly gone on to bigger, better things since the series ended.