Carl Banks (one special): Banks, a New York Giants player, appeared during the celebrity performance of "Put Down the Duckie" in Put Down the Duckie: The Sesame Street Special
Tyra Banks acted out the word "struggle" and sang "The ABC Song" with Abby Cadabby (Note: This video was posted on YouTube, following the season finale)
Tiki Barber defined "quest" and helped sing "Set Your Piggies Free"
Laura Bush (one segment): In episode 4032, the First Lady reads an original book called Wubba Wubba Wubba to Elmo, Big Bird, and some children.[11] Bush has also appeared on international adaptation of the series Alam Simsim in Egypt and Galli Galli Sim Sim in India.
Reggie Bush discussed the word "appetite" in Music Magic
C-3PO explains to R2-D2 that the thing he is in love with is a fire hydrant in episode 1396. "It is better to have loved a fire hydrant than never to have loved at all." (This was their second appearance; the first was in episode 1364)
John Candy (appeared as his Yosh Shmenge character from SCTV, but the segment was pulled after its initial airing due to complaints from Polish groups. He also made an appearance as Shmenge in "Sesame Street, Special".)
Michael Davis juggled foods, a bowling ball, and trash across the street in episode 1959, as well as juggling Oscar's pets; he was thought to be imaginary by Big Bird.
Whoopi Goldberg talked with Elmo about skin color and hair texture
Jeff Goldblum (appeared in Episode 2687 as Bob's brother, Minneapolis Johnson, who went on a quest for a golden cabbage in Snuffy's cave with Big Bird, Snuffleupagus, and Bob)
The Goo Goo Dolls performed the song "Pride", which is based on their hit single "Slide"
Mark Ingram (one special): Ingram, a New York Giants player, appeared during the celebrity performance of "Put Down the Duckie" in Put Down the Duckie: The Sesame Street Special
Jeremy Irons appeared during the celebrity performance of "Put Down the Duckie" in Put Down the Duckie: The Sesame Street Special, 1988
Bill Irwin (appeared in a season 23 sketch as a man caught in a windstorm, appeared in season 25's remake of "A New Way To Walk", appeared as "Professor Television" in season 28 and currently plays Mr. Noodle)
Jesse Jackson (one segment): Civil rights activist Jackson recited the free verse poem "I Am – Somebody" to numerous children and adult gathered around him on 123 Sesame Street
James Earl Jones (guest starred in the first season (1969), reciting the alphabet and counting numbers.[18] He later hosted the 10th anniversary special, where he was reunited with his former drama teacher, Will Lee.)
Sean Landeta (one special): Landeta, a New York Giants player, appeared during the celebrity performance of "Put Down the Duckie" in Put Down the Duckie: The Sesame Street Special
Michael Landon (appeared with the rest of the Bonanza cast in season 2)
Andrea Martin (appeared as Edith Prickley in several segments, guest starred as Wanda Falbo, Word Fairy, and narrated the television segments on Elmo's World)
Frances McDormand as a fictionalized version of herself working as a department store worker (from the television special/VHS release Big Bird Gets Lost)
John Moschitta Jr. (appeared in season 16 as a man whose children's names have a name beginning with every letter, as well as a spokesman for "Peter Piper's P Products")
Liam Neeson (appeared reciting the alphabet for Ernie in season 30)
Karl Nelson (one special): Nelson, a New York Giants player, appeared during the celebrity performance of "Put Down the Duckie" in Put Down the Duckie: The Sesame Street Special
Conan O'Brien (one segment, two specials): O'Brien has guested on Sesame Street itself, as well as two special productions. While trying to deliver a tape in the Elmopalooza special, Big Bird runs through the set of Late Night with Conan O'Brien, where he is interviewing the Yip Yips; also seen is Andy Richter. O'Brien appeared in a celebrity montage of "Sing", for 2004 DVD What's the Name of That Song.
Fred Penner sings 'I Had a Rooster' and 'The Cat Came Back' on "Canadian Sesame Street"
Chad Pennington (one segment): Pennington, a New York Jets player, appeared in season 38 (2007), along with other Jets, Elmo, and Elmo's goldfish Dorothy
Rhea Perlman (as the "old woman who lived in a shoe" that landed on Big Bird's nest after a hurricane, also appeared with husband Danny DeVito in the 25th anniversary special)
Katy Perry appeared in a skit with Elmo parodying her song "Hot n Cold". The skit was intended to air on the actual series, but the producers overturned their decision due to parent's reaction to Perry's revealing wardrobe.[23]
Ahmad Rashad defines the word "gigantic" in episode 4152
Lou Rawls (one segment): Rawls appeared in a segment during the first season, to sing the alphabet. He dismissed the concept of using cue cards for the performance, but reversed such decision when he forgot the order of the letters.[24]
Rachael Ray (two segments): one baking pumpernickel bread and one describing the word 'amazing'
Christopher Reeve (two segments): Reeve first appeared on the show in 2000 for two segments; in one Reeve says the alphabet with Ernie and Ernie's Rubber Duckie, the other he demonstrates the independent living skills he developed after acquiring a disability in 1995 (quadriplegia)
Paul Reubens (two segments): Reubens, as Pee-wee Herman, recited his own version of the alphabet in a 1987 insert. Reubens was also recorded for the celebrity version of Put Down the Duckie.
Malvina Reynolds season 4 cast member: A folksinger, songwriter, and political activist, then 73-year-old Reynolds appeared on the show performing songs "This House Is Your House".
Andy Richter (one special): While trying to deliver a tape in the Elmopalooza special, Big Bird runs through the set of Late Night with Conan O'Brien, where Conan is interviewing the Yip Yips; Richter is seen in the background very briefly.
Sally Ride (one segment): In January 1984, the year immediately following her historic mission, Ride taped a segment on the series where she talks about how A is for astronaut, while Grundgetta visits[25]
Kelly Ripa unable to find the slip of paper on which she wrote the meaning of "frustrated" in episode 4144 and played by Mail Carrier Kelly
Tim Robbins (two segments and one street scene): Robbins appeared in two 1990 insert segments. In the first, he performs at Prairie Dawn's pageant about the seasons; Robbin's then 5-year-old daughter Eva appeared at the end of the segment.[26] The second, first aired episode 3960, he talks about surprises with Elmo. In a 1997 street scene, Robbins rents a room at the Furry Arms Hotel, which he shares with Muppet animals. Talking to Sesame Street Magazine in 1997, Robbins listed three reasons for appearing on the show: his children, Eva, Jack Henry, and Miles.[26] Robbin's then five-year-old son Miles taped three segments with Baby Bear that appeared throughout the 29th season.[26]
Doris Roberts (two appearances in one special): In the introduction to Sesame Street special The Street We Live On, Roberts is one of the celebrities in the "My Favorite Sesame Street Moments" clip. She later appeared in a celebrity montage of the song "Dance Myself to Sleep".
Julia Roberts Elmo demonstrates to her how to look scared
Richard Stoltzman appeared on episode 2633. During the first street scene, He plays The Sesame Street theme song on the clarinet. Later on in the episode. He explains to Oscar that playing the clarinet with just the pieces will not make a good sound. When he built the pieces together, he can play. He plays Rhapsody in Blue.
Emma Stone acts out the word "balance" with Abby Cadabby
Carrie Underwood as "Carrie Underworm" performing "The Worm Anthem"
Usher defined "volunteer" with Elmo, he also sang "The ABCs of Moving You" with various muppets (over 115 million YouTube views),[29] defined "unique" with Bert
Lillias White season 21–24 cast member, 1 street scene: White appeared from 1989 through 1993 as "Lillian", a regular cast member of the show, winning a Daytime Emmy Award for her performance. During her stint, she also voiced the lead singer of The Squirrelles, a Muppet singing group, consisting of three squirrels. She returned in 2006 as a guest for a season 37 street scene, playing Gabi and Miles' kindergarten teacher Ms. Walsh, in a flashback sequence.
Brian Williams demonstrates "squid" in a separately-recorded segment, and also as a guest news-anchor reporting that nobody on Sesame Street is sharing (due to a disease called "Mine-Itis")
Robin Williams (seven segments): Williams appeared numerous times in the 1990s and 2000s. In the first, aired in 1992 as episode 2963, Williams uses his shoe to demonstrate what makes something alive. Robin then appeared in a celebrity version of "Monster in the Mirror". Another segment has Robin comparing the similarities and difference between himself and a Muppet robin. In another segment, Williams asks Elmo and the kids whether they would allow a nonsense talking, horned two-headed stranger to play baseball with them. In 2000's episode 3684, Williams talks to Elmo about what you can do with a stick. In 2001's episode 3923, Williams shows off the wonders of feet. The Two Headed Monster shows up to play. In 2012's episode 4280, Williams defines the word "conflict" with The Two Headed Monster.