The Adventures of Elmo in Grouchland (or simply Elmo in Grouchland) is a 1999 American musical adventure comedy film directed by Gary Halvorson (in his feature directorial debut) from a screenplay written by Mitchell Kriegman and Joey Mazzarino, based on a story conceived by Kriegman.

It stars Mandy Patinkin and Vanessa Williams alongside Muppet performers Kevin Clash, Caroll Spinney, Steve Whitmire, and Frank Oz.

It features songs written by a wide range of songwriters, including Siedah Garrett, Jeff Elmassian, Andy Rehfeldt, Martin Erskine, Seth Friedman, and Michael & Patty Silversher, with a score composed and conducted by John Debney.

Telly Monster, roller skating out of control, comes and accidentally swipes the blanket, leading to a chase around Sesame Street.

Unwilling to wait for Oscar to return, Elmo dives into the bottom of the trash can, where he finds his blanket snagged on a door.

A kind Grouch girl named Grizzy tells Elmo that his blanket is in Huxley's castle at the top of the faraway Mount Pickanose.

With Oscar's help, some of the Sesame Street residents (Zoe, Telly, Gordon, Maria, Cookie Monster, and Big Bird) go to Grouchland to find Elmo, but when they encounter a Grouch police officer and try to ask him for assistance, they end up getting arrested as they are informed that it is against the law to ask for help in Grouchland, and they get sent to jail.

The police officer releases the Sesame Street residents so they and the Grouches can go to Huxley's castle to fight for their trash and rescue Elmo.

Elmo falls into a basket as Huxley decides to make him and his blanket both his property by using a claw to put them on his conveyor stamper.

Additional characters performed by: Drew Allison, Bruce Lanoil, Bill Barretta, Bob Lynch, John Boone, Ed May, R. Lee Bryan, Tim Parati, Leslie Carrara, Annie Peterle, Lisa Consolo, Andy Stone, Jodi Eichelberger, Lisa Sturz, Rowell Gormon, Kirk Thatcher, Mary Harrison, Matt Vogel, Rob Killen and Matt Yates All the puppeteers who performed the primary Sesame Street characters (such as Kevin Clash, Jerry Nelson, Caroll Spinney and Fran Brill) were called to Wilmington, North Carolina for the table read on May 19, 1998.

The site's consensus states, "This fun and moral tale entertains both first-time Sesame Street watchers and seasoned veterans.

In total, The Adventures of Elmo in Grouchland earned back less than half its $26 million budget, grossing $11,683,047 during its two-and-a-half-month theatrical run.

[11] The film inspired a trilogy of children's books, published in 1999 by Random House: Happy Grouchy Day, The Grouchiest Lovey, and Unwelcome to Grouchland.