Her early credits include the series Falcon Crest and In the Heat of the Night (both 1988), Tequila and Bonetti (1992), Can't Hurry Love (1995–1996), and ER (1997–1998), and the drama film Leaving Las Vegas (1995).

Hargitay founded the Joyful Heart Foundation, which provides support to people who have been sexually abused, and became a certified rape counselor.

She has engaged in initiatives to support domestic violence shelters, raise awareness about untested rape kits, and contributed to other causes.

Hargitay was born at Providence Saint John's Health Center in Santa Monica, California, the daughter of actress and 1950s-era sex symbol Jayne Mansfield.

[11] A few weeks later, Mansfield married the director Matt Cimber, who had directed her in a 1964 production of the William Inge play Bus Stop.

The accident ripped off the top of the car, instantly killing Mansfield,[15] her boyfriend Sam Brody, and the driver.

Asleep in the back of the vehicle, Mariska, then three-and-a-half years old, was left with a zigzag scar on one side of her head.

[26] She portrayed police officer Angela Garcia in the 1992 series Tequila and Bonetti and appeared in the two-part fourth season finale episode of Seinfeld, where they had her read for the role of Elaine Benes in "The Pilot".

[29] Two years later, Hargitay portrayed Didi Edelstein, the sexy next-door neighbor, in the 1995 sitcom Can't Hurry Love, which starred Nancy McKeon.

In 1997, Hargitay played detective Nina Echeverria on the drama series Prince Street, and had a recurring role as inept desk clerk Cynthia Hooper during the fourth season of ER.

[15] Casting for the lead characters of NBC police procedural television drama series Law & Order: Special Victims Unit occurred in the spring of 1999.

For the female lead – Detective Olivia Benson – Samantha Mathis, Reiko Aylesworth, and Hargitay were being considered.

For the male lead – Detective Elliot Stabler – the finalists were Tim Matheson, John Slattery, and Christopher Meloni.

Meloni and Hargitay had auditioned in the final round together, and after the actors left, there was a moment of dead silence, after which Wolf blurted out, "Oh well.

She received UCLA's TFT Distinguished Alumni Award in 2011 and was honored at the school's June commencement ceremony.

[34] During the last months of her pregnancy in 2006, Hargitay took maternity leave from SVU, and was temporarily replaced by Connie Nielsen, who portrayed Stabler's temporary partner Dani Beck.

[35][36] In late December 2008, Hargitay suffered a partially collapsed lung after taking a fall during a stunt on the set of SVU.

[40] During negotiations in April for a new contract, the duo attempted to receive a percentage of the show's profits as other high-profile Law and Order actors had done in the past.

[47] In July 2021, Hargitay suffered a broken ankle after taking a fall in the rain while leaving the screening of Black Widow.

[58] In California, the domestic violence services budget was in a major crisis, and shelters were forced to turn women away.

[58] Hargitay has worked with Michigan Police and Wayne County Prosecutor Kym Worthy to raise awareness about the statistics of untested rape kits.

[61] As of November 2010, the Joyful Heart Foundation has sent over 5,000 women and children on therapeutic programs in New York, Los Angeles, and Hawaii, which combine yoga, meditation, massage, journaling, and swimming with dolphins.

[63] The Foundation works with several brands to create products supporting the cause, including Me&Ro, Michael Stars, and AZIAM's Wife Lover Tanks.

[64] On September 27, 2011, Hargitay donated $100,000 to her alma mater, the UCLA School of Theater Film and Television for scholarship.

"[67][68] On August 28, 2004, in Santa Barbara, California, Hargitay married Peter Hermann, an actor whom she met on the set of Law & Order: SVU,[69][70] on which he plays the recurring role of defense attorney Trevor Langan.