Bennett grew up in Massapequa Park, New York. After appearing in numerous commercials, Bennett began his official acting career at the age of 18 as Jamie, in the 2009 TV movie "Totally for Teens". However his television career sprouted after he appeared as Greg the Intern in the pilot episode of the Comedy Central sketch comedy series Michael & Michael Have Issues.
Bennett starred in The Virginity Hit, released in October 2010. Described as a "documentary style comedy," Bennett stated in an interview that the film's "directors gave us cameras in our spare time, and he said do pranks, talk amongst yourselves, do things and film that. So we did, and most of the movie is what we filmed. So I feel like 20% is scripted but the rest is all real."
The Virginity Hit was produced by Funny or Die founders Will Ferrell and Adam McKay; in an interview with MTV News, Bennett stated that reception towards the film has been "very positive...I’m glad that people are getting that it's not just another teen sex romp. It’s a film with heart and a bit of a soul and deep-down it’s a cool love story."
Bennett co-starred as Robbie Shapiro in the Nickelodeon sitcom Victorious. He was nominated for a 2011 Nickelodeon Kids' Choice Award (UK) in the category of "Nick UK's Funniest Person". The show ran from March 27, 2010 to February 2, 2013.
Bennett independently released an EP of songs that he wrote, Warm Fuzzies, on May 20, 2012.
On February 2, 2016, Bennett made a Snapchat press conference announcement about his new album Terminal Cases. Bennett claims "it's a concept album about my parents divorce where every song is inspired by different Robin Williams movies." It was released on June 10, 2016.
In March 2013 it was announced that Bennett would host a web series for the YouTube channel Nerdist. On the series, entitled "Nerdy Jobs," Bennett will go behind the scenes of many "Nerdy" jobs to show how interesting they are.
On June 23, 2014, Bennett was featured in the popular YouTube video "The Slap" as one of the participants. He was also asked to be the love interest for Ariana Grande's character in her One Last Time music video, she is his close friend and former co-worker from Victorious.
In 2015 Bennett guest-starred in Game Shakers in the episode "Tiny Pickles". He also contributed to The Stanford Experiment and Me Earl Dying Girl in 2015, and Fresh off The Boat in 2016.