Happiness Is a Warm Blanket, Charlie Brown is the 45th Peanuts animated television special, released in 2011. It was the final primetime special based on the comic strip, before the franchise moved to Apple TV in 2020. The special is the first one produced without Bill Melendez on the production team, following his death in 2008. It is also the first special without the direct involvement of Peanuts creator Charles M. Schulz, Lee Mendelson Productions or Bill Melendez Productions (it is unknown, though, if Lee Mendelson also worked on this special). In addition, it is the first Peanuts special produced in part under Warner Bros. Television, which holds the home media distribution rights to the Peanuts specials.

The special was released on DVD on March 29, 2011, and first aired on television on October 1, 2011, on Teletoon in Canada. The special premiered in the United States on Thanksgiving Day, November 24, 2011, at 8:30PM ET/PT on Fox, the first Peanuts special to air on the network; with this airing, Peanuts specials have aired on all four major networks. Coincidentally, the first half of the film's original Fox broadcast in 2011 competed directly with a Peanuts special that aired at the same time on ABC ("The Mayflower Voyagers" from This Is America, Charlie Brown). The special aired again on November 23, 2012 (the day after Thanksgiving, so as not to directly compete with the other Peanuts specials) and December 17, 2013.

The program special is particularly notable in that the characters/animation are drawn in a 1950s/early-1960s style, and it uses only characters from that time period (including Violet, Shermy, and Patty), except for the inclusion of one later character, Woodstock, and intermediate-era characters Frieda, Faron, 5, 4, and 3 appearing briefly as extras; and even pays homage to the very first Peanuts strip, from October 2, 1950 (when Charlie Brown has a flashback sequence).

The title recalls the 1960s Peanuts phrase "Happiness Is a Warm Puppy," which became a cultural reference.