The 29-year-old landed the job in 2017 and said it was her "dream" to be working alongside Ant & Dec.
However, she will not be reprising the role when the show returns next year.
An ITV spokesman said: "Scarlett Moffatt won't feature as a contributor in the 2020 series of Saturday Night Takeaway.
"We thank Scarlett for all of her hard work on the show and will announce details of the new series nearer transmission."
Moffatt, who is from Bishop Auckland in County Durham, is close friends with Geordie stars Ant & Dec.
She rose to fame after appearing on Gogglebox and won the 16th series of I'm A Celebrity ... Get Me Out Of Here! in 2016.
Moffatt recently appeared in Channel 4 documentary The British Tribe Next Door.