Jennette McCurdy was born on June 26, 1992 in Long Beach, California, and grew up in Garden Grove, California. She has three older brothers named Marcus, Scott, and Dustin. She is of Dutch, English, French, Irish, Italian, and Swedish descent. McCurdy reportedly became interested in acting upon watching Star Wars Episode IV: A New Hope after her mother recovered from breast cancer. However, in a 2014 appearance on the podcast You Made It Weird with Pete Holmes, she said that this was not entirely true.
McCurdy started her acting career in 2000 at the age of eight on MADtv. Since then she appeared in television series, including CSI: Crime Scene Investigation, Malcolm in the Middle, Lincoln Heights, Will & Grace, The Penguins of Madagascar, Zoey 101, True Jackson, VP, Law and Order SVU, Medium, Judging Amy, The Inside, Karen Sisco, Over There, and Close to Home. In 2003, she had the chance to act with her inspiration, Harrison Ford, in the film Hollywood Homicide. In 2005, she was nominated for a Young Artist Award for Best Performance in a Television Series – Guest Starring Young Actress for her performance in Strong Medicine as Hailey Campos. She has also appeared in several commercials, such as one for Sprint and a public service announcement on crossing the road safely.
In 2007, she won a starring role in the Nickelodeon TV series iCarly as Sam Puckett, a series she would be a part of until its end in 2012. In 2008, she was nominated for a Young Artist Award for her work on iCarly and her performance as Dory Sorenson in the TV movie The Last Day of Summer. She was nominated for a 2009 Teen Choice Award in the Favorite TV Sidekick category for her work on iCarly. She played Bertha in Fred: The Movie, a movie based on a YouTube series about Fred Figglehorn.
In June 2008, McCurdy announced on her official website that she was working on her debut album. The first single, "So Close", was released on March 10, 2009. On May 19 her cover of the Amanda Stott song "Homeless Heart" was released. The song was released in honor of McCurdy's recently deceased friend Cody Waters, who died at the age of nine from brain cancer, and 20% of the proceeds were donated to the Cody Waters Foundation. She met Waters through St. Jude Children's Research Hospital. In mid-2009, McCurdy signed with Country music label Capitol Records Nashville. On April 16, 2010, samples of select songs from McCurdy's upcoming debut country album were released online. The song clips were released in order for fans to vote for which one they believed should be McCurdy's first single. "Not That Far Away" received the most votes, and was released to country radio on May 24, 2010 and iTunes on June 1.
She released an EP on August 17, 2010, which included "Not That Far Away" and three new songs: "Stronger", "Put Your Arms Around Someone", and "Break Your Heart". The iTunes version included "Me with You" as a bonus track. "Stronger" was later included on Now That's What I Call Music! Vol. 35, released on August 31, 2010. McCurdy's second single, "Generation Love", was released as a digital download on March 22, 2011, followed by its release to radio April 25, 2011. Capitol Nashville released McCurdy's self-named seven-track EP on February 8, 2012 at clothing retailer Justice. The full-length, ten-track edition was released to iTunes on June 5, 2012 and is her first full-length album. On July 11, 2012, Fanlala released an interview with McCurdy in which she confirmed that she has since left Capitol Records Nashville, saying, "I'm kind of Between projects right now. I actually just left Capitol Records recently. I'm really just deciding what else I want to do next. Right now I'm working on my new show, and I'm just figuring out where I should take my music from here." On July 31, 2012, How to Rock released an interview with McCurdy, in which she talked about her acting and music careers. A follow-up interview was released on August 8, in which McCurdy reflects on her music career.
She starred alongside Ariana Grande in the Nickelodeon series Sam & Cat, reprising her role as Sam Puckett, with Grande reprising her role as Cat Valentine. The series' plot centers on the girls becoming roommates and starting their own babysitting business. It premiered on June 8, 2013. In 2014 McCurdy along with good friend and former co-star Miranda Cosgrove were absent from the Nickelodeon Kids' Choice Awards. Explaining her absence, McCurdy stated that Nickelodeon put her in an "uncomfortable, compromising, unfair situation" where she had to look out for herself, and McCurdy and Grande were having problems with the network over their respective salaries, and that McCurdy accused Nickelodeon of paying Grande more money. The network placed Sam & Cat into hiatus. The network initially stated that the hiatus was planned and that the series was not cancelled. On July 13, 2014, Nickelodeon announced that, after only one season, Sam & Cat was cancelled. In an interview on Entertainment Pop, McCurdy mentioned that she later made up with Grande.
On August 13, 2014, McCurdy launched the online show What's Next for Sarah?. She served as the star of the series as well as the writer of the show, along with duties as executive producer and editor. She says that the show is based loosely on her life and that the character she plays, Sarah Bronson, is based on her.
In 2015, she began starring in the Netflix drama series Between. It was also announced that she would star in teen comedy Little Bitches alongside Virginia Gardner and Kiersey Clemons.
In August 2016, McCurdy signed a deal to develop projects with digital production company Canvas Media Studios to further utilize her social media connections with fans. She also starred as Claire in the psychological thriller film Pet.
In 2011 McCurdy began writing articles in the Wall Street Journal. She has written a total of eight articles for the paper, on various topics ranging from Shirley Temple to body shaming and the corporate culture of smoke and mirrors. She is a columnist for Seventeen magazine. She has also written for The Huffington Post.
In 2013, McCurdy moved to Studio City, California.
McCurdy composed an article titled "Off-Camera, My Mom's Fight With Cancer", which was published in the Wall Street Journal in June 2011. It describes in detail her mother Debra's ongoing battle with cancer and how her family coped with the situation. The article also features advice from McCurdy on living with such a situation. On September 20, 2013, her mother died after battling cancer for 17 years.