The star, who has multiple resort performances under her belt including the Illuminations Switch On Concert, will be joined on this year's billing by The Voice 2020 winner Blessing Annatoria.
Fleur will headline on Saturday October 16. Also taking to the stage will be artist John Newman and and BAFTA award-winning dance group Diversity.
SlimeFest returns to Blackpool Pleasure Beach Arena for a six show extravaganza opening on the Saturday until Monday October 18.
It will once again be hosted by Jordan Banjo and Perri Kiely as well as brand new hosts social media stars and singers Max & Harvey, and TikTok sensation Holly H
More tickets have now been released to the Saturday and Sunday shows.
Further acts will be added to the SLIMEFEST 2021 line up in the coming weeks.