When Law & Order premiered in 1990, no one could have predicted that a show about "two separate yet equally important groups" in the criminal justice system would go on to last for 20 seasons. Even more unbelievable is the fact that the most successful of its many spin-offs, Special Victims Unit, has been on the air for 23 seasons and counting. The franchise is so popular, in fact, that in 2021, NBC announced it would be reviving the original series, a decade after its cancellation. And while many actors have found fame investigating crime or prosecuting the offenders, only a few have stuck around for more than a couple of seasons. These are the actors who spent the most time on Law & Order.
