Jim Henson originated the character in 1955 on his local television series, Sam and Friends. Brian Henson described his father's performance as Kermit as "coming out of his own personality—was a wry intelligence, a little bit of a naughtiness, but Kermit always loved everyone around and also loved a good prank." He continued to perform the character until his death in 1990. Henson's last known performance as Kermit was for an appearance on The Arsenio Hall Show to promote The Muppets at Walt Disney World. Henson died twelve days after that appearance.

Kermit has been featured prominently on both The Muppet Show and Sesame Street. However, he had a prominent career before Sesame Street's debut in 1969, as he starred in Sam and Friends, and numerous Muppets made guest appearances on Today from 1961 and The Ed Sullivan Show from 1966.

Kermit performed the hit singles "Bein' Green" in 1970 and "The Rainbow Connection" in 1979 for The Muppet Movie, the first feature-length film featuring the Muppets. The latter song reached No. 25 on the Billboard Hot 100. Kermit's iconic look and voice have been recognizable worldwide since, and in 2006, the character was credited as the author of Before You Leap: A Frog's Eye View of Life's Greatest Lessons, which is an "autobiography" told from the perspective of the character himself.

Kermit has made numerous guest appearances on popular television shows, including co-hosting individual episodes of a number of long-running talk shows. On April 2, 1979, Kermit guest-hosted The Tonight Show Starring Johnny Carson to promote The Muppet Movie. From 1983 to 1995, the French political satire show Le Bébête Show used copies of various Muppets to parody key political figures, and Kermit renamed "Kermitterrand", embodied President François Mitterrand.

Jim Henson's characters, including the Muppets, have inspired merchandise internationally, with Chris Bensch, chief curator of Rochester, New York's The Strong National Museum of Play, reporting "There seems to have been a particular craze for Kermit the Frog in Japan," likely due to the "cuteness appeal." Baby Kermit plush toys became popular in the 1980s after the success of Muppet Babies. In 1991, one year after Jim Henson died, merchandise featuring Kermit and other Muppet characters was being sold at Disney theme parks, causing Henson Associates to file a lawsuit against Disney for copyright infringement. Henson alleged that the "counterfeit merchandise" falsely indicated that the characters belonged to Disney, although the latter company had the right to exercise use of the characters due to an earlier licensing agreement. The Henson Associates highlighted a T-shirt displaying Kermit, the Disney brand, and a copyright symbol. Disney representative Erwin Okun said the lawsuit was "outrageous" and "an unfortunate break with the legacy of a fine relationship with Disney that Jim Henson left behind". Disney later acquired the Muppets, and thusly, clothes, toys and souvenirs depicting Kermit and the Muppets continued to be sold at Disney theme parks and stores.

Kermit appears in Muppet*Vision 3D, an attraction that opened in 1991 at Disney's Hollywood Studios at Walt Disney World in Lake Buena Vista, Florida. The character was formerly featured at the attraction version in Disney California Adventure Park, at the Disneyland Resort in Anaheim, California, until its closure in 2014. Kermit also appears at the Magic Kingdom at The Muppets Present...Great Moments in American History. He also appeared in two parades; Disney Stars and Motor Cars Parade held at Disney's Hollywood Studios until 2008 and Disney's Honorary VoluntEars Cavalcade that was held during 2010 at the Magic Kingdom and Disneyland.

As an April Fool's joke, Kermit hosted CNN's Larry King Live in 1994 and interviewed Hulk Hogan. Kermit was also a semi-regular during various incarnations of Hollywood Squares, with other Muppets such as Big Bird and Oscar the Grouch also making appearances on the original Hollywood Squares.

Kermit was also given the honor of being the Grand Marshal of the Tournament of Roses Parade in 1996. The Macy's Thanksgiving Day Parade has featured a Kermit balloon since 1977.

Kermit was one of the original main Muppet characters on Sesame Street. Closely identified with the show, Kermit usually appeared as a lecturer on simple topics, a straight man to another Muppet (usually Grover, Herry Monster or Cookie Monster), or a news reporter interviewing storybook characters for Sesame Street News. He sang many songs on the show, including Bein' Green, and appeared in the 1998 video The Best of Kermit on Sesame Street.

For a brief demonstration at MuppetFest (a 2001 Muppet fan convention), Muppet performer John Kennedy performed Kermit opposite Whitmire's performance of young Kermit (from Kermit's Swamp Years). Kennedy also performed Kermit for Muppets Ahoy!, a 2006 Disney Cruise Line stage show (though Whitmire performed Kermit for the first few shows). Muppet performer Artie Esposito briefly performed Kermit in 2009 for a few personal appearances (an appearance on America's Got Talent, an appearance at the MTV Video Music Awards, and at the 2009 D23 Expo with Rowlf the Dog as part of a tribute to Jim Henson).

On November 14, 2002, Kermit the Frog received a star on the Hollywood Walk of Fame. The star is located at 6801 Hollywood Blvd.

On Kermit's 50th birthday in 2005, the United States Postal Service released a set of new stamps with photos of Kermit and some of his fellow Muppets on them. The background of the stamp sheet features a photo of a silhouetted Henson sitting in a window well, with Kermit sitting in his lap looking at him.

Kermit was also the grand marshal for Michigan State University's homecoming parade in 2006.

In March 2007, Sad Kermit, an unofficial parody, was uploaded to the website YouTube, showing a store-bought Kermit puppet performing a version of the Nine Inch Nails song "Hurt" in a style similar to Johnny Cash's famous cover version. In contrast to the real Kermit character's usual family-friendly antics, the video shows the puppet engaging in drug abuse, smoking, alcoholism, performing oral sex on Rowlf the Dog, smashing a picture of Miss Piggy (with a breast exposed) and attempting suicide. The video became an Internet meme. The Victoria Times Colonist called it an "online sensation". The Chicago Sun-Times said it "puts the high in 'Hi-ho!'" The London Free Press said "Sad Kermit is in a world of pain". The Houston Press described it as the "world's most revolting web phenomenon". SF Weekly described the unauthorized video as "ironic slandering." Clips have been featured on the Canadian television series The Hour, where host George Stroumboulopoulos speculated that the Kermit version of "Hurt" was inspired by the Cash version rather than that of Nine Inch Nails.

Unlike the rest of the show's Muppets, Kermit was never any property of Sesame Workshop and has rarely been a part of the show's merchandise. When Sesame Workshop bought full ownership of its characters from the Jim Henson Company for $180 million, Kermit was not included in the deal. The character now belongs to The Muppets Studio, a division of the Walt Disney Company. His first Sesame Street appearance since Disney-ownership was in the show's 40th-season premiere on November 10, 2009.

A biography has been developed for Kermit the Frog as if he was an actual living performer rather than a puppet character. According to this fictional biography, he was born in Leland, Mississippi alongside approximately 2,353 siblings, though a 2011 "interview" on The Ellen DeGeneres Show has him state that he was from the swamps of Louisiana.

In 2013, the original Kermit puppet from Sam and Friends was donated to the Smithsonian Institution in Washington, D.C. for display in the pop culture gallery. In 2015, the Leland Chamber of Commerce in Leland, Mississippi opened a small museum containing puppets and memorabilia dedicated to Kermit.

Kermit has also appeared in a popular meme in which he is shown sipping tea, "one used when you sassily point something out, and then slyly back away, claiming that it's not [your] Business." The photo is taken from "Be More Kermit," a Lipton advertisement that aired in 2014, and was adapted into the "But That's None of My Business" meme by African American comedians on the Tumblr blog Kermit the Snitch, making appearances on Twitter, Instagram and Facebook. Charles Pulliam-Moore of the TV station Fusion praised "But That's None of My Business" as "a symbol for the comedic brilliance born out of black communities on the internet," but Stephanie Hayes of Bustle magazine slammed the memes as racist and obscene.

Kermit's legacy is also deeply entrenched in the science community. One of the famous WP-3D Orion research platforms flown by the NOAA Hurricane Hunters is named after Kermit. The other is named after Miss Piggy. In 2015, the discovery of the Costa Rican glass frog Hyalinobatrachium dianae also attracted viral media attention due to the creature's perceived resemblance to Kermit, with researcher Brian Kubicki quoted as saying "I am glad that this species has ended up getting so much international attention, and in doing so it is highlighting the amazing amphibians that are native to Costa Rica and the need to continue exploring and studying the country's amazing tropical forests."

In November 2016, a new meme surfaced of Kermit talking to a hooded version of himself which represents the self and its dark inner thoughts. It involves captioning of a screenshot taken from the Muppets Most Wanted movie of Kermit and Constantine looking at each other.

Following Henson's death, veteran Muppet performer Steve Whitmire was named Kermit's new performer. In 2017, Whitmire seemed to imply in a blog post that Jim Henson had asked him to assume the role before he died, though Jim's daughter Cheryl Henson claimed Brian had selected him after Jim's death. Whitmire's first public performance as Kermit was at the end of the television special The Muppets Celebrate Jim Henson in 1990. He remained Kermit's principal performer until 2016. Disney announced that Matt Vogel would be taking over as the performer and voice for Kermit on July 10, 2017. Whitmire later revealed that he had not chosen to voluntarily leave the role, but rather, had been recast by Muppet Studios in October 2016. In an interview with The Hollywood Reporter later in July 2017, Whitmire elaborated he was fired for two reasons: long-term creative disagreements over Kermit's characterization and prolonged labor union negotiations that delayed his involvement in Muppet-related productions.