Cilla Fisher and Artie Trezise said they would bow out after three decades when this year's Christmas tour finishes.
In a statement on the group's wesbsite, they said: "After 30 glorious years, the creators of The Singing Kettle, today announced that their forthcoming Christmas Tour would be their final stage appearance and at the same time unveiled exciting plans for the future of Scotlands Favourite Children's Entertainers.
"Husband and wife, Cilla and Artie feel the time is right to introduce new blood to continue the huge success of the Singing Kettle brand.
"Cilla and Artie plan to continue their involvement with The Singing Kettle and will take on backstage creative roles.
"Cilla will continue to write songs for future productions while Artie will produce the stage shows as well as direct the DVDs and CDs
"The good news is that the company have begun the process of recruiting a new female cast member to join Gary Coupland & Kevin Macleod for the new tour starting in March next year."
Cilla and Artie's final show will be on February 17 next year at Edinburgh Festival Theatre.
The group’s most popular song is known by almost every family in Scotland, with its irresistible refrain: "Spout. Handle. Lid of Metal. What's inside the Singing Kettle?"
They have performed in hundreds of venues including the Palladium in London to the Royal Palace in Jordan, and have sold more tickets at the SECC in Glasgow than Take That, Wet Wet Wet, and Dire Straits.
The group were formed in 1982 by Cilla, 60, and Artie, 65, both now MBEs. Artie, from Cupar in Fife, had given up his teaching career in the 1970s to tour as a folk singing duo with Cilla at folk festivals around the world.
Cilla, who has penned over 260 original songs for the group, came up with the concept of recording popular children’s folklore songs.
In 1982, they released a children’s album called the Singing Kettle which featured Scottish folk songs, as well as tunes they picked up from touring America.
With the success of the album they began touring primary schools before moving on to theatre shows across Scotland. On the back of their success, they recruited their friend, musician Gary Coupland, known as the Music Man, in 1985 to help expand the shows.
Originally, they were based on clues for songs inside colourful kettles but, over the years, developed into more of a narrative musical.
Popular shows include The Boogie Woogie Zoo, The Time Machine, Pirates, Wild West Show, Busy Road Show, World Tour, Funny Farm, and Homemade Band.
Artie and Cilla have two children, James Trezise and Jane Fisher. Jane performed in the group as one of the ‘Kettle kids’, but left the group in 2001 to perform in electronic punk band Motormark in 2001. She is now in a band called Fangs.
Former stage manager Kevin MacLeod, 43, took over from Jane as a full member in 2001. He played Bonzo the dog, one of the most popular characters in the group and a merchandising best seller for the Singing Kettle.