Mo Chaudry, 49, will formally apply today - days after the BNP had to change its whites-only constitution because it breached equality laws.
The Pakistan-born businessman, who is worth £60million, admitted last night: "I will not be welcomed with open arms."
Despite blasting the party as racist, he vowed: "I want to stand up and be counted - and expose the BNP for what they are.
"I want to antagonise them and attend their meetings, find out what makes them tick."
Muslim Mo, who made his fortune from water parks, appeared on Channel 4's Secret Millionaire in December.
He handed out cash to worthy causes in the Asian community of Leeds.
The dad of three, from Newcastle-under-Lyme, Staffs, said: "I live near Stoke, which is becoming a BNP stronghold - and don't want it being known as a racist city."