The Marx Brothers were an iconic American comedy troupe, led by Julius "Groucho" Marx (1890-1977) and included brothers Harpo and Chico (all stage and film work), Zeppo (in early films), and Gummo (in the stage era). The brothers performed on stage and in a series of successful farcical movies, including A Day at the Races, A Night at the Opera, A Night in Casablanca, Duck Soup, and Animal Crackers, amongst others. Groucho, with his greasepaint moustache, thick cigar, spectacles, and wavy hair, developed the persona of consummate wisecracker and con artist.
As a solo performer, Groucho hosted the radio and television game show You Bet Your Life, a series which relied less on the suspense of competition than on the host's patter and rapport with contestants.
- The song "Lydia, the Tattooed Lady," first performed by Groucho Marx in the film At the Circus, was used in The Muppet Show episode 102.
- Gonzo, upon entering George Burns' dressing room in episode 210, is addressed as "One of the Marx brothers: Groucho, Chico, Harpo, and Gonzo."
- Peter Sellers tended to slip in a Groucho voice every now and again in his career. He appears as a gypsy violinist on The Muppet Show episode 219, being told "play" by the Muppets. Temporarily breaking away from his gypsy voice, Peter said in Groucho style, miming cigar-holding, "Listen, any more talk like that and I will play!"
- Spike Milligan assists Sam the Eagle with an oration in The Muppet Show episode 317, in which he comes out on stage representing an English gentleman. However, he speaks in such a thick brogue, that Sam can't understand him and claims he is not speaking the Queen's English. Spike replies in an eyebrow-raising, faux cigar-holding Groucho-Marx pose, "Why should I? She never speaks any of mine."
- In a 1970s Sesame Street segment, David and Maria imagine Gordon with a variety of hairstyles. At one point, David imagines him with "hair like Harpo."
- In Christmas Eve on Sesame Street, Oscar says to Maria "He'll come back- he's part homing pigeon," echoing Chico's line in At the Circus.
- In The Muppets Go Hollywood, Dick van Dyke catches Fozzie Bear with a bag of cement, planning to add his own signature to the Grauman's Chinese Theatre sidewalk. Fozzie explains, "I know it's crazy -- but, you see, my dream is to be here with all the Hollywood comedian greats, you know? My pawprint right here with them, like Abbott and Costello, and the Marx brothers, and -- oh, look, the Ritz brothers!"
- Sesame Street Episode 1576 features a group of birds called the "Canary Brothers", two of which are named Zeppo and Gummo Marx.
- A picture of Groucho adorns Fozzie's locker in The Muppets Take Manhattan.
- A pair of Marx brothers posters (including one for A Day at the Races) are seen on the wall in Hey, You're as Funny as Fozzie Bear. Fozzie also does a brief imitation of Groucho at one point.
- In Sesame Street: 20 and Still Counting, Kermit tries to interview people on the street. He meets Grover, who calls out, "Ice cream! Get your Tootsie-Frootsie ice cream!" This is in reference to a scene from A Day At the Races in which Chico Marx calls out the same thing.
- Neon caricatures of the brothers are shown in the background of The Comedy Store in The Jim Henson Hour episode "Miss Piggy's Hollywood."
- The Merrill Lunch Hungerdunger McCormack All Accountant Marching Society, from The Muppets Celebrate Jim Henson is a reference to the "Hungerdunger, Hungerdunger, Hungerdunger and McCormack" scene from Animal Crackers.
- In Episode 3366 of Sesame Street, Joey and Davey Monkey disguise themselves using Groucho glasses. Gordon gets a hold of a pair and exits the scene mimicking Groucho. The scene is punctuated with a music button of "Hooray for Captain Spaulding" from Animal Crackers.
- In Sesame Street Episode 3718, Telly Monster calls out to various customers in the back booth of Hooper's Store to see if they want sandwiches. He addresses one unseen customer "You, with the Groucho glasses!"
- According to designer Stephen Rotondaro in production notes for The Adventures of Elmo in Grouchland, "The Mayor of Grouchland is our version of Groucho Marx."
- In Sesame Street Episode 3826, Maria and Luis portray two doctors resembling (in voice and appearance) Groucho and Chico. Their names, Dr. Quackenbush and Dr. Bushenquack, are a reference to Groucho's role as "Dr. Hackenbush" in A Day at the Races.
- Elmo appears as Groucho, Telly Monster as Harpo, and Herry Monster as Chico in A Brief History of Motion Pictures.
- On September 7, 2011, Oscar the Grouch tweeted, "“The only ‘a-peeling’ thing about a banana is the part that goes in the TRASH!” – Grouch Marx, Grouch comedian. Love that guy!" 
see also: Duplicate characters
- Duck Soup featured Groucho and Harpo Marx in a famous mirror scene: in an empty hallway, Harpo would mime to be the reflection of Groucho, confusing him in the process. A similar routine appears in The Muppet Show episode 104 featuring Kermit and The Mechanical Wind-up TV Show Host.
- In Sesame Street Episode 3140, Gina and Savion return from a screening of Duck Soup and quote Groucho's "taxi" line.
- The popular "mirror scene" from Duck Soup was recreated in The Treasure of Peg-Leg Wilson story arc, in which Kismet mirrors Kermit's every move. After Kermit leaves, he comments, "You know, I've always wanted to do that."
"Groucho glasses," combining Groucho's trademarked spectacles with fake nose, mustache, and (usually) thick eyebrows, are a recurring Muppet prop.
|Fozzie Bear wears a pair in The Muppet Movie when he first appears on stage at the El Sleezo Cafe.|
|A picture of Kermit the Frog wearing Groucho glasses (and using Groucho's trademark walk and cigar) appeared on one of the cards in the 1980 Kermit the Frog Card Game.|
| ||The Muppets use the glasses as a disguise when raiding the Mallory Gallery in The Great Muppet Caper.|
|The Fozzie Bear Action Figure came with a pair as an accessory that can be worn and removed.|
|A Sigma mug places the prop beside Fozzie Bear.|
|Red Fraggle dons a version of Groucho glasses in the Fraggle Rock episode "The Secret Society of Poobahs."|
|The Wild Impresario holds a rubber chicken wearing a pair of Groucho glasses in The Ghost of Faffner Hall episode "Notation: The Sign That Gets the Sound."|
|In the Shalom Sesame episode "Kids Sing Israel", Moishe Oofnik tries to make a request under the guise of "Groucho Oofnik," complete with Groucho glasses.|
|In a Sesame Street sketch, Grover installs his latest model of sunglasses on Kermit; a modified pair of Groucho glasses with ears. Kermit then slips into a Groucho impression, stating "This is the most ridiculous thing I've ever heard!"|
|Oscar the Grouch pulls out a pair of Groucho glasses during "Just the Way You Are" on Sesame Street.|
|In the video Sing Yourself Silly, Maria and Luis don a pair of Groucho glasses and imitate his cigar-holding pose as they remark "Now that's silly!".|
|Baby Fozzie wears circular Groucho glasses (sans eyebrows) in the Muppet Babies episode "Fozzie's Last Laugh."|
|Baby Scooter and Baby Skeeter wear the glasses as a disguise to get snacks from the kitchen in the Muppet Babies episode "Pigerella."|
|Baby Gonzo dresses as Groucho in the Muppet Babies episode "Masquerading Muppets."|
|Baby Scooter etches a Groucho face on Baby Gonzo during the song "Look a Little Bit Closer" in the Muppet Babies episode "Beauty and the Schnoz."|
|In order to demonstrate that a nose can be used to wear a disguise over it, Wolfgang the Seal wears similar glasses (bigger nose, no mustache) in Sesame Street Episode 3265.|
|Joey and Davey Monkey, Ruthie and Gordon all use pairs of these in Episode 3366 of Sesame Street.|
|Telly's "Secret Disguise Kit" depicts a pair of Groucho glasses on the case in Episode 3644 of Sesame Street.|
|Gonzo and Rizzo wear Groucho glasses in a deleted scene from Muppets from Space.|
|Elmo can be seen wearing Groucho glasses in Music Works Wonders.|
|In one "Letter of the Day" segment, Cookie Monster disguises the letter M cookie in a pair of Groucho glasses to prevent him from eating it.|
|In the online music video for "Bohemian Rhapsody," Fozzie sports Groucho glasses along with another standard comedy prop, the fake-arrow-through-the-head popularized by Steve Martin.|
|The reverse side of the Muppet Parodies series of postcards show a small picture of Kermit wearing Groucho glasses. Several Muppet posters were sold shrink-wrapped against a sturdy poster board, donning the same image on a sticker.|
|The Memorybot uses Groucho glasses as a disguise to fool Elmo in The Best of Elmo 2.|
|Dr. Beemer wears a pair of glasses while giving Baby Fozzie his checkup in Baby Fozzie Visits the Doctor.|
|Fozzie is shown wearing the glasses multiple times in Fozzie's Funnies.|
|In the storybook I Want to See..., Baby Rowlf's pet fish Tillie wears a pair of Groucho glasses.|
|The Sesame Street song "Everything's Coming Up Noses" ends with Harvey Fierstein wearing a pair of Groucho glasses.|
|A Monsterpiece Theater sketch based on the musical Anything Goes featured dancers in Groucho glasses singing "Anyone's Nose".|
|A set of floating Groucho glasses talks to Elmo in Elmo's World: Eyes. The glasses enter to "Hello, I Must Be Going" from Animal Crackers, and in a reference to You Bet Your Life, they prompt Elmo to say the "secret word", which signals a duck to drop from the ceiling.|
|In a 2011 commercial for Orange cross-promoting The Muppets in the UK, Fozzie Bear decorates the advertiser's logo with Groucho glasses.|
|In a Vila Sésamo sketch, Garibaldo keeps failing to draw a portrait of Bel. On his third try, he draws Bel with Groucho glasses. Bel says it looks nothing like her, but Garibaldo takes her over to a mirror and puts Groucho glasses on Bel.|
| ||A Martian wears a pair, disguising himself as an Earth person in order to study the species, in Episode 4805 of Sesame Street.|
|Nina in When You Wish Upon a Pickle|