The "makeunder" show, hosted by Jenny Frost, encourages people to return to a more natural look.
Wayne Rooney's cousins Natalie and Stephen, Lady Victoria Hervey, and Dirty Sanchez members Pritchard and Dainton are among the participants in the fourth series.
Their looks will be assessed by Philip Olivier, Scott Mills, Daily Star columnist Joe Mott, actor Alex Carter, comedian James Redmond and former X Factor star Lloyd Daniels, as well as by members of the public.
The participants will also face the panel after their "makeunders" and Frost will meet up with them a few weeks later to find out whether they have adopted the changes.
The show will also feature more editions of 'Frost's Fixes', in which Frost gives viewers beauty tips in areas including eye bags and blisters.
The fourth series of Snog, Marry, Avoid is expected to begin on BBC Three in January.