Elmo is a Muppet character on the children's television show Sesame Street. He is a furry red monster and currently hosts the last full 15 minute segment on Sesame Street, Elmo's World, which is aimed at toddlers. His puppeteer, Kevin Clash, uses falsetto to produce his voice. Elmo's parents, Mae and Louis, speak with Southern American accents.

Elmo is self-described as three-and-a-half years old and characteristically avoids pronouns, referring to himself in the third person (e.g. "Elmo has a question" rather than, "I have a question"). Sesame Street staff writer Nancy Sans once described Elmo's origins: "There was this extra red puppet lying around and the cast would pick him up sometimes and try to create a personality, but nothing seemed to materialize.  The puppet was performed by Caroll Spinney in the early 1970s, Brian Muehl from 1979 to 1981, and the late Richard Hunt from 1981 to 1984. Sans continues that "…one day [in 1984], Kevin Clash, a talented puppeteer, raised him up and brought energy and life into Elmo and from that day forward we would all write for Elmo. Kevin's performance inspired the writers to develop Elmo's character". John Tartaglia, Matt Vogel, and Jim Martin have all been secondary performers for the character, providing movement for Elmo's arms and legs, particularly in green-screen shots.

After becoming a regular guest on The Rosie O'Donnell Show, Elmo began touring the talk-show circuit. He has appeared on Martha Stewart Living and Martha, The Tony Danza Show, Rove Live, Wait Wait…Don't Tell Me!, and The View. Elmo and a developmental expert gave babysitting tips on the June 18, 2005 episode of Teen Kids News. He has also appeared on Emeril Live, helping Emeril make (non-alcoholic) eggnog during a Holiday Special shown in December 2008. Kevin Clash and Aaron Neville were also guests on this show. On a special episode of Oprah called "The Faces Behind The Famous Names," Kevin Clash and Elmo appeared at the same time.

Elmo was the star of the 1999 full-length, theatrically released motion picture Elmo in Grouchland. He also starred in the film Elmo Saves Christmas.

Elmo also appeared in a fifth season episode of The West Wing along with his friends Zoe and Big Bird. In that episode, Elmo receives a medical checkup from Abbey Bartlet, the First Lady (who is making a guest appearance on Sesame Street), and cheekily questions her about the validity of her medical license.

Elmo is the only non-human or puppet ever to testify before the U.S. Congress. At the request and with the assistance of Rep. Duke Cunningham, he testified before the House Appropriations Subcommittee on Labor, Health and Human Services and Education in April 2002, urging support for increased funding in music education.

Emeril and Elmo's Healthy Start was a special featuring Elmo and Emeril Lagasse that aired on November 4, 2005 at 8 p.m. as part of the Food Network's second annual "Cook With Your Kids Week". The special was produced in conjunction with Sesame Workshop's Healthy Habits for Life program.