Wittels' body was discovered by his assistant at 12 p.m. in the 2200 block of North Hobart Boulevard, said Los Angeles Police Department Officer Rosario Herrera.
Police suspect Wittels died from a drug overdose, but the cause of death will be determined by the county coroner's office.
On “Parks and Rec,” whose seventh and final season concludes Feb. 24, Wittels also served as a writer and occasionally appeared as an animal control staffer.
Wittels grew up in Houston, Texas, where he began performing stand-up comedy in junior high. After graduating from Emerson College in 2006, he moved to Los Angeles to launch his career in comedy.
He sent his stand-up video to Upright Citizens Brigade in Hollywood, eventually gaining a spot on its most popular show, “Comedy Death-Ray,” and later, a gig at the popular comedy and night club Largo.
Sarah Silverman saw Wittels perform at Largo and later offered him a job writing for her eponymous Comedy Central show.
As a stand-up comic, Wittels toured with Aziz Ansari and Louis C.K. He also wrote for the HBO series “Eastbound and Down.”
After moving to Los Angeles, Wittels wrote that he began noticing shameless self-promotion as a standard feature of communication – a trend that became more prevalent with social media, much to his annoyance.
He coined the word “humblebrag” and in 2012 published a book, “Humblebrag: The Art of False Modesty.”
“It was bragging, but it wasn’t just bragging,” Wittels wrote. “It was a type of bragging that included some amount of fake modesty, which somehow made it acceptable to do.”
His death prompted an outpouring of grief and praise on Twitter, where Wittels' @humblebrag account had nearly a quarter of a million followers.
"Such heartbreaking news about Harris Wittels. A really funny guy," wrote Seth Meyers, the host of NBC's "Late Night."
"Harris Wittels was an incredibly funny person who has left us way too soon," wrote the Twitter account for comedy website Funny or Die. "He will be missed."
For breaking news in California, follow @MattHjourno.