Skins will conclude in 2013 with a seventh series, featuring a number of former actors from the three generations of casts.
However, Hoult confirmed to The Sun that he would not be one of those returning.
"No, I'm not going to be doing it. I loved Skins but I don't think I can fit it in," he said.
"I'm filming Mad Max in Namibia, which will mean I'm away for ages."
Hoult played Tony Stonem for two series of the teen drama in 2007 to 2008. Since leaving the show, he has starred in movies such as X-Men: First Class and A Single Man.
Skins writer Jamie Brittain confirmed earlier this year that Jack O'Connell will be reprising his role as James Cook in the seventh-series finale.