is a live British Saturday morning children's magazine entertainment programme on CBBC and BBC Two,[1] first broadcast on 30 September 2017.

Every week, the series broadcasts live from BBC Pacific Quay Studios, in Glasgow.

Series 3 started on 1 February 2020 but was paused due to the 2019–2020 Coronavirus pandemic, the show was subsequently presented from Joe Tasker, Harpz Kaur, and (puppeteer) Dave Chapman's houses via video-link under the name Saturday Mash-Up!

In 2018 and 2019, special programmes were also produced as part of the CBBC Summer Social TV coverage.

On Saturday 10 and 17 September 2022 the show was off-air due to the UK national period of mourning for the death of Queen Elizabeth II.

Two celebrity guests each compete in a driving challenge through the studio and backstage passing through themed areas including Mash-Up!

Two celebrities must push a shopping trolley into a pyramid of 800 toilet rolls to see how many they can collect.

While the crew count the rolls, Johnny Nelson played a game with the contestant called "Jonny's random supermarket item pricing game while we count the toilet rolls".

Large food items are thrown in, including mystery superfoods with plus or minus points written on.

After running in the wheel for thirty seconds, celebs are taken to Joe's relaxation area and asked to "Say Ahhhh" while the points are added up.

After some dentist themed jokes, the scores are announced and the celebrities are added to the leader board.

For the final segment of the program, the viewers watching the show vote on who they want to be covered with gunge, from a selection of two, three or four options.

Celebrities who have been gunged/slimed include Steve Backshall, DanTDM, Vick Hope, Kimberly Wyatt, Naomi Wilkinson, Lindsey Russell (twice), New Hope Club, Road Trip, Oti Mabuse, Lewys Ball, Olivia Grace and Lovevie, Colson Smith, Mark Rhodes, Briony Williams, Cat Henstridge, Bella Ramsey, Dani Harmer and Jenny Richardson.

Finally, the theme music plays one more time as the hosts and guests say goodbye.