Mariska Hargitay is a trained rape crisis counselor.

According to an article in TV Guide, cast members are often approached by sexual abuse survivors, who thank them for portraying these types of stories on the air correctly.

Ice-T was originally contracted for only four episodes, but he enjoyed working on the series so much, that he asked to join the cast permanently.

Richard Belzer carried his role of Detective John Munch over from Homicide: Life on the Street (1993) and Homicide: The Movie (2000). He also played John Munch in Law & Order (1990), which had several crossover episodes with "Homicide", an episode of The X-Files (1993), an episode of The Beat (2000), an episode of Law & Order: Trial by Jury (2005), the season three finale of Arrested Development (2003), and an episode of The Wire (2002). This is a record for appearances by an actor playing the same character on different programs. Detective John Munch was also played on Sesame Street (1969), voiced by Joey Mazzarino.

Season N: N letters on the name of any episode (N > twelve). All episodes of season thirteen have thirteen letters in the title; season fourteen, there are fourteen letters in each episode title; season fifteen: fifteen letters.

Mariska Hargitay keeps a photo of her mother Jayne Mansfield on her desk on the set.

Peter Hermann (Attorney Trevor Langan in thirty-two episodes) is Mariska Hargitay's real-life husband.

Two years before joining the cast as a series regular, Diane Neal (Casey Novak) appeared in an episode playing a woman accused of raping a male stripper.

Richard Belzer originally asked Dick Wolf if Munch could join Law & Order (1990) as Lennie Briscoe's new partner. But Jesse L. Martin had already been cast. Belzer later heard about this new series, and asked to join, on the condition that Dean Winters be cast as his partner. Winters was still under contract with Oz (1997), and had to leave the show after the first thirteen episodes. Winters returned as a recurring cast member in the fourteenth season.

Odafin's (Fin's) last name, Tutuola, means "the gentle one" in Yoruba.

Christopher Meloni was starring on Oz (1997) simultaneously with this series. He eventually left "Oz" because he felt that he could no longer do both shows at the same time. But Meloni missed "Oz", and decided to return the next season. He decided that being able to work on two great shows simultaneously was worth the physical and emotional toll.

The series was originally proposed under the title Sex Crimes, and unrelated to the Law & Order (1990) brand. NBC thought the title was too harsh, and after discussions between network executives and Dick Wolf (creator of Law & Order (1990)) it became part of the Law & Order brand, debuting as Law & Order: Special Victims Unit (1999).

The only prime time drama to be spun-off from two separate shows: Law & Order (1990) and, through the character of Detective John Munch, Homicide: Life on the Street (1993)

At the start of season thirteen, episode titles were no longer one word. Season thirteen is also the first season without Detective Elliot Stabler (Christopher Meloni).

Many of the actors on the show previously starred on the HBO drama Oz (1997) including Dean Winters and BD Wong. Most notable, and ironic, is Christopher Meloni (Detective Elliot Stabler) who played a sadistic rapist and murderer on Oz, and then hunted them on this show. In addition, many guest stars have also appeared in this show and Oz. Reg E. Cathey has the same last name of "Querns" in both shows. Kirk Acevedo, J.K. Simmons (as Emil Skoda), Michael Potts, Lee Tergesen, Kathryn Erbe, Harold Perrineau, Robert John Burke (as Lieutenant Tucker), Scott William Winters (Dean Winters brother who has played a police officer), R.E. Rodgers, as well as many other cast members have appeared on both television programs.

After the World Trade Center attack on September 11, 2001, NBC ordered the opening credits for the 2001-2002 season re-edited to remove images of the ill-fated buildings.

Over the course of the series, Mariska Hargitay has been completely absent from only nine episodes.

Olivia and Elliot were named after Producer Dick Wolf's children. The name Olivia shows up in Benjamin Bratt's television family (as one of Rey's daughters), then there's Dr. Olivet.

First season regular guest star Chris Orbach, who played Ken Briscoe, is the son of Jerry Orbach, who played Lennie Briscoe on Law & Order (1990). Ken Briscoe is Lennie's nephew.

Rafael Barba (Raúl Esparza) is this show's first regular male Assistant District Attorney.

Until the fourth episode of season twelve, the precinct scenes were filmed in North Bergen, New Jersey. After this episode, the show moved its studio space to the Chelsea Piers section of Manhattan that was previously occupied by Law & Order (1990).

The second longest-running and most successful spin-off of Law & Order (1990). The franchise includes: Law & Order (1990), Law & Order: Special Victims Unit (1999), Law & Order: Criminal Intent (2001), Law & Order: Trial by Jury (2005), Law & Order: UK (2009), Law & Order: LA (2010), and Law & Order True Crime (2017).

According to Executive Producer Ted Kotcheff, the lead parts of Detective Olivia Benson and Detective Elliot Stabler came down to three actors and three actresses: Mariska Hargitay, Reiko Aylesworth, and Samantha Mathis for the role of Benson, and Christopher Meloni, Nick Chinlund, and John Slattery for the role of Stabler.

Peter Scanavino made his debut as a janitor, named Johnny Dubcek in season fourteen, episode thirteen, "Monster's Legacy" before he joined the team by the name of Dominick "Sonny" Carisi, Jr., at the start of season sixteen.

Many members of the main cast in the Law & Order universe usually have a guest spot on one of the shows before they become regular cast members. Peter Scanavino (Sonny Carisi) is the only member of the Law & Order cast to have had a guest starring role on four of the six Law & Order series before landing his role.

Season eighteen originally included an episode titled "Unstoppable", loosely based on the allegations of sexual assault made against Donald Trump. It was postponed before the 2016 Presidential election, and shelved indefinitely in 2017.

Several of the main characters have served in the United States Military in some capacity. Dr. Warner was in the Air Force, Detective Stabler was in the Marines, Captain Cragen was in the Green Berets (as revealed on the original Law & Order (1990)) and Detective Tutuola was an Army Ranger.

As of the end of season seventeen, Olivia Benson and Dominick Carisi, Jr. are the only detectives to have not been shot in the line of duty.

Season eighteen marks the first time in which Tamara Tunie (Dr. Warner) does not appear.

The baby character, Noah Porter was played by twin babies, Skyler Dubow and Bradley Dubow (but mostly Bradley). However, in season seventeen and eighteen, the role of Noah was played by Jack Nawada-Braunwart. The character was re-cast again in season nineteen, and is currently played by Ryan Buggle.

Before Kelli Giddish landed her role as Detective Amanda Rollins, she first appeared as a rape victim by the name of Kara Bawson in season eight, episode twelve, "Outsider".

In season fifteen, it appears that Detective Olivia Benson (Mariska Hargitay) now has a larger, fourteen carat, rectangular necklace charm of the same earlier design. She received it from her psychiatrist after her kidnapping and torture, where the original had been held as evidence at the time.

Although viewers had long wondered if the character George Huang was gay (as is BD Wong), his homosexuality was not verified until season eleven, episode five, "Hardwired". Even for a show and a franchise that is notoriously parsimonious with personal information about its characters, that is an extraordinarily long time for basic personal information to be withheld about a regular character on a television series (by contrast, both Detectives Elliot Stabler and Olivia Benson were established as heterosexual during the show's first season through dialogue and subplots about Stabler's marriage and Benson's dating habits).

The following statement appears at the beginning of every episode: "In the criminal justice system, sexually-based offenses are considered especially heinous. In New York City, the dedicated detectives who investigate these vicious felonies are members of an elite squad known as the Special Victims Unit. These are their stories."

Pop star Taylor Swift is such a fan of the show that she named her pet cat "Olivia Benson" in tribute to the lead character.

Season one is the only season in which Christopher Meloni is credited as "Chris Meloni".

Jennifer Love Hewitt was considered for the role of Detective Amanda Rollins, after previously guest starring as Vicki Sayers in season twelve, episode three, "Behave".

The photo in the opening credits for Dann Florek (from the beginning of the show) and Ice-T (starting with the second episode of season two) did not change until season nine, when the entire cast received updated photos (coinciding with the debut of Adam Beach). The photo for Mariska Hargitay has changed seven times (season one has one photo, seasons two through four, and the first four episodes of season five have a second, the rest of season five has a third, seasons six through eight have a fourth, seasons nine and ten have a fifth, seasons eleven through fourteen have a sixth, and season fifteen to the present have a seventh). Christopher Meloni, Richard Belzer, and BD Wong got new photos starting with the fifth episode of season five(coinciding with the debut of Diane Neal as Assistant District Attorney Casey Novak) before they all received new photos in season nine. Diane Neal had one photo for season five, a second for seasons six and seven, a third for season eight, and a fourth for season nine. Tamara Tunie, who first appeared in the opening credits in season seven, received a second photo for season eight, and a third photo for seasons nine through twelve, before she was removed from the credits in season thirteen.

Uses a re-mixed version of the theme music from Law & Order (1990).

This series shared many cast members with ER (1994), including Mariska Hargitay, John Cullum, Kellie Martin, Erik Palladino, Michael Michele, David Krumholtz, Mare Winningham, Leland Orser, Maria Bello, CCH Pounder, Donal Logue, Alex Kingston, Gloria Reuben, and Elizabeth Mitchell.

The series has been the longest currently running American live-action primetime television series since the cancellation of Law & Order (1990) in 2010. It is therefore the last remaining such series to have premiered in the 1990s.

The badge numbers for each Detective is as follows: Detective Elliot Stabler's shield number was 6313. Detective (later Lieutenant) Olivia Benson's shield number is 4015. Detective Odafin "Fin" Tutuola's shield number is 3198. Detective Nick Amaro's shield number is 0840. Detective Dominick Carisi, Jr.'s shield number is 0188. Detective Amanda Rollins' badge number is 0458.

Detective Benson's full name is Olivia Margaret Benson.

Season thirteen marked the first time that this show was broadcast without any other Law & Order branded shows on the air (a position that it had maintained until Law & Order True Crime (2017) aired). Law & Order (1990) ended in 2010, while Law & Order: Criminal Intent (2001) and Law & Order: LA (2010) ended in early 2011, several months before season thirteen premiered.

Season nine has the distinction of having the largest number of main cast members with nine. The season nine cast was comprised of: Mariska Hargitay, Christopher Meloni, Richard Belzer, Diane Neal, Ice-T, Adam Beach, BD Wong, Dann Florek, and Tamara Tunie.

To date, season nine is the shortest season of the series, consisting of only nineteen episodes.

Prior to season thirteen, season seven was the only one in which Kathy Stabler (Isabel Gillies) did not make an appearance.

Isabel Gillies and Daniel Sunjata, who had recurring roles as Kathy Stabler and a CSU technician, respectively, both played murder suspects on Law & Order (1990); Gillies in season eight, episode twenty-one, "Bad Girl", and Sunjata in season fifteen, episode twelve, "Mammon".

With the commencement of its fifteenth season in September 2013, the series surpassed Knots Landing (1979) as the longest running live-action spin-off series in American prime time television history. Knots Landing (1979), a spin-off of Dallas (1978), ran for fourteen seasons from 1979 to 1993.

After several years of playing Detective Olivia Benson and being exposed weekly to issues of sexual assault, domestic violence, and child abuse, in 2004 actress Mariska Hargitay started a foundation (called Joyful Heart) to help heal survivors' trauma and bring an end to the overwhelming backlog of untested rape kits and un- or under-investigated rape cases. In 2018 Hargitay produced an HBO documentary, "I Am Evidence," about the enormous backlog of untested rape kits in police custody across America.

This show has frequently used The City University of New York Lehman College campus in Bronx, New York, as a school location for many of their episodes.

Many cast members from the Netflix series Orange Is the New Black (2013) have made appearances.

Amanda Rollins is originally from Loganville, Georgia.

Having played Olivia Benson for 19 seasons since 1999, Mariska Hargitay is tied with Amanda Blake, who played Miss Kitty Russell in Gunsmoke (1955) from 1955 to 1974, as the longest serving actress in the same role in the history of American live-action primetime television. The only male actors to have played a character for a longer period of time in American live-action primetime television history are James Arness as Marshal Matt Dillon in Gunsmoke (1955) from 1955 to 1975, Kelsey Grammer as Dr. Frasier Crane in Cheers (1982) from 1984 to 1993 and Frasier (1993) from 1993 to 2004 and Richard Belzer as Detective John Munch in Homicide: Life on the Street (1993) from 1993 to 1999 and Law & Order: Special Victims Unit (1999) from 1999 to 2013.

Seasons six, seven, thirteen and nineteen mark the only seasons in which Captain Ed Tucker (Robert John Burke) did not appear.

Until season fifteen, Detective Olivia Benson's address was 203 West 89th Street Apartment 4E (or 4D, depending on the episode).

Many cast members from The Wire (2002) appeared on this show.

In season eight, episode ten, "Scheherazade", Paget Brewster (Supervisory Special Agent Emily Prentiss on Criminal Minds (2005)) played the daughter of Brian Dennehy, a dying criminal. She returned with a different name as the District Attorney of the Public Integrity Unit.