Harris Wittels was born in Oklahoma City, Oklahoma, the son of Dr. Ellison Wittels and Maureen (née Davidson) Wittels, and raised in Houston, Texas. Wittels described his father as “the funniest dude alive”. He had one older sister, voiceover actress Stephanie Wittels. He was Jewish, and had his bar mitzvah at Temple Emanu-El, across the street from Rice University. Wittels attended High School for the Performing and Visual Arts in Houston. In 2006, he graduated from Emerson College, where he was a member of Sigma Alpha Epsilon, with a degree in television and video production. After performing stand-up comedy in Los Angeles, Wittels met Sarah Silverman and became a writer on The Sarah Silverman Program in 2007. He also wrote for the 2007 and 2008 MTV Movie Awards. When The Sarah Silverman Program ended in 2010, Wittels became a staff writer and executive story editor for Parks and Recreation during the show’s second season, then later co-producer during the third season and executive producer during the fourth. His writing credits included the episodes “Media Blitz”, “94 Meetings” and “Dave Returns”. He also appeared on the show as Harris, a dim-witted animal control employee. Wittels also wrote for the programs Secret Girlfriend and Eastbound and Down. In 2012, Wittels was cast as a co-star in Sarah Silverman’s NBC pilot Susan 313 along with June Diane Raphael and Tig Notaro, which was not picked up. Wittels was a frequent guest on the Earwolf podcast Comedy Bang Bang and was known for the recurring segment “Harris’ Foam Corner” (originally titled “Harris’ Phone Corner”, which debuted on Episode 31 of CBB), during which he read jokes and observations saved on his phone that were deemed to be not good enough for his act. The jokes were typically lambasted by host Scott Aukerman. Also on the Earwolf network, Wittels hosted the Analyze Phish podcast, where he attempted to convince friends to enjoy the band Phish.

Wittels was a member of the band Don’t Stop or We’ll Die, along with comedians Paul Rust and Michael Cassady. He was the band’s drummer and provided backing vocals. In 2010, Wittels coined the phrase “humblebrag” on Twitter. He wrote for Grantland on the subject of notable “humblebrags”, the act of boasting about one’s life and then downplaying it. The popularity of the feed led to a book, Humblebrag: The Art of False Modesty, published in 2012. Humblebrag was designated the “most useful” word of 2011 by the American Dialect Society. In August 2013, NBC picked up an untitled Wittels sitcom, about a slacker still living with his parents while dealing with his whiz kid younger brother, a multi-millionaire entrepreneur in high school. In a November 19, 2014 interview on the podcast You Made It Weird, Wittels openly discussed his personal life and history of drug addiction with host Pete Holmes. He said he had done drugs recreationally since he was 12. He said his drug usage got “out of hand” because of a breakup with a woman he felt was “perfect” for him in every way, except that she and her family were Scientologists, which he described as a “deal-breaker.” He said he began to rely on oxycodone to deal with his stress over the relationship, his work on various television pilots and writing the Humblebrag book. “It was easier just to take drugs and do it all. I wrote that entire book on so much drugs,” Wittels said. “That’s a humble brag.” During the podcast, Wittels told Holmes he had gone to rehab for a second time after becoming addicted to heroin, and had just gotten out of rehab a month earlier. “[Sobriety is] still fresh. I haven’t figured it all out,” he said.

On February 19, 2015, multiple news outlets reported that Wittels was found dead of a possible drug overdose in his Los Angeles home. The Los Angeles Police Department said Wittels’ assistant found his body around noon on a couch with no signs of trauma and unspecified drug paraphernalia in his house. On February 18, during his stand-up set at The Meltdown, he talked about living sober and said he was in “a good place”. A toxicology report was expected to take six to eight weeks. On July 28, 2015, the official cause of death was confirmed to be a heroin overdose. Following news of his death, Wittels’ friends and colleagues, including Aziz Ansari, Amy Poehler, Dan Harmon, Sarah Silverman, and Scott Aukerman paid tribute to him. Ansari wrote on his blog that the two had been planning to move to New York City together in March, and he shared his favorite memory of Wittels during an appearance on Conan. The series finale of Parks and Recreation, “One Last Ride”, aired a final frame with the message, “We love you, Harris.” Similarly, there’s a frame saying “Dedicated to the Memory of Harris Wittels” before the closing credits on the Aziz Ansari: Live at Madison Square Garden comedy special that was released March 6 on Netflix. In the first season finale of Aziz Ansari and Alan Yang’s show Master Of None, on which Wittels was a writer, an intertitle states “This series is dedicated to the memory of our dear friend Harris Wittels.”