Law & Order is a media franchise composed of a number of related American television series created by Dick Wolf and produced by Wolf Entertainment. They were originally broadcast on NBC, and all of them deal with some aspect of the criminal justice system. Together, the original series, its various spin-offs, the TV film, and crossover episodes from other shows constitute over 1,000 hours of programming.

Shared characters and fictional organizations, such as Hudson University and the New York Ledger tabloid newspaper, serve as connecting links between the shows. Many supporting characters, such as district attorneys, psychologists, and medical examiners are also shared among the shows. Occasionally, crossovers of main characters or shared storylines between two of the shows will occur. A few major characters have also left the cast of one show within the franchise only to eventually join another. The music, style, and credits of the shows tend to be similar, with the voice-over in the opening of every series performed by Steven Zirnkilton. The shows share the iconic "dun, dun" sound effect of a jail cell locking, created, along with the theme songs, by Mike Post. Past episodes of the American series are in syndication with local over-the-air stations, along with cable channels such as USA Network and Bravo (both owned by the franchise's production company, NBCUniversal), Warner Bros Discovery's TNT, WGN America, E. W. Scripps Company's network Ion Television, and AMC Networks' SundanceTV and WeTV, showing episodes sometimes up to six times a day. Its ubiquity on the NBCUniversal fledgling streaming platform Peacock ("...19 zillion reruns...") was noted by The Wall Street Journal in January 2024.

In October 2012, Law & Order: Special Victims Unit showrunner/executive producer Warren Leight said of the future of the Law & Order franchise, "[Dick Wolf and I] sometimes talk in general terms of where (the franchise) could go. I'm curious to see if there's another iteration somewhere down the line", before adding: "We try hard to maintain a certain level of quality which I think is why the shows sustained in reruns so well. And I'd like to believe there's room for another generation in some way." In February 2015, NBC was purported to have interest in bringing back the flagship Law & Order as a limited series. On September 28, 2021, NBC announced that a 21st season had been ordered.

Seven television series make up the Law & Order franchise: Law & Order, Special Victims Unit, Criminal Intent, Trial by Jury, LA, True Crime, and Organized Crime. All series in total amount to 1,423 episodes across 70 seasons of television.

Law & Order, a crime procedural, features both a police investigation of a crime discovered during the cold open, and a prosecution case set forth by the New York County District Attorney, at the Manhattan DA's office. The first thirty minutes of an episode typically features a lead detective trio. On May 14, 2010, NBC announced that it was canceling the original series, although various spin-offs would continue. The series finale aired on May 24, 2010. Wolf briefly attempted to continue the series on cable, but the series "moved into the history books".

On September 28, 2021, NBC announced that a 21st season had been ordered. At the start of season 25, the police team consists of Senior Detective Vincent Riley (Reid Scott), and Lieutenant Jessica Brady (Maura Tierney), while the counterparts on the legal side are: Executive Assistant District Attorney Nolan Price (Hugh Dancy), Assistant District Attorney Samantha Maroun (Odelya Halevi) and Manhattan District Attorney Nicolas Baxter (Tony Goldywn)

SVU follows the cases investigated by NYPD Captain Olivia Benson (Mariska Hargitay) and her Manhattan Special Victims Unit colleagues. The show's focus is on detectives who investigate sexually based crimes and crimes against children, the elderly, and the disabled. At the start of season twenty-seven, these detectives included characters Sgt. Odafin Tutuola (Ice-T), Det. Joe Velasco (Octavio Pisano), Det. Terry Bruno (Kevin Kane), Capt. Renee Curry (Aimé Donna Kelly) and Sgt. Amanda Rollins (Kelli Giddish), while Peter Scanavino co-stars as ADA Dominick Carisi Jr.

Organized Crime follows the cases investigated by former SVU detective Elliot Stabler (Christopher Meloni) as part of the task force within the Organized Crime Control Bureau headed by Sergeant Ayanna Bell (Danielle Moné Truitt). The show's focus is on detectives who investigate mobsters and other criminal syndicates. On March 31, 2020, NBC ordered a 13-episode season of a then-untitled Special Victims Unit spin-off starring Christopher Meloni as Stabler, now in an NYPD organized crime task force. Meloni had previously starred on SVU from 1999 to 2011. The show's title was confirmed to be Law & Order: Organized Crime. Writer Craig Gore was fired from the series in June following backlash from a social media post. When NBC announced its fall schedule on June 16, Organized Crime was the only new show on the schedule, slotted for Thursdays at 10 p.m. Eastern. Due to filming stoppages related to COVID-19, the season was shortened to eight episodes and premiered on April 1, 2021. At the start of season four, other detectives included characters detective Jet Slootmaekers (Ainsley Seiger) and detective Bobby Reyes (Rick Gonzalez).