John James McCoy is a fictional character in the television drama Law & Order. He was created by Dick Wolf and Michael S. Chernuchin and has been portrayed by Sam Waterston during both the show's original run from 1994 to 2010 and since its return in 2022. He is the longest-tenured character on the show, appearing in 18 seasons. He has appeared in 382 episodes of Law & Order, four episodes of Law & Order: Special Victims Unit, two episodes of Law & Order: Trial by Jury, two episodes of Homicide: Life on the Street, and the made-for-TV movie Exiled.