Using his established Coppernob brand, Fields will open womenswear shop-in-shops and stores of his own. He intends to build a nationwide chain.
The first branch, measuring about 800 sq ft (75 sq m), is scheduled to open in Debenhams' Oxford Street store in October.
Another five such outlets are already planned, and Fields is in discussions with landlords to find suitable standalone premises.
Oliver Kaye, formerly Selfridges' womenswear operations manager, has joined Coppernob as retail operations director. Barbara Horspool, former head of womenswear design for Marks & Spencer, will advise as a non-executive.
Fields believes there is a gap in the market for a fashion retailer that prioritises design in a high street clothing environment that often lacks distinctiveness.
'It's tough out there, but original designs will trade well,' he said. 'The opportunity for us is the uniqueness of the product we offer and the way we offer it. We have a very clear idea about who the customer is.'
Fields' past retail experience includes opening the cult Rag Freak store in Kensington in 1970 and 1980s Snob chain, which was sold to Etam in 1987.
He also ran Coppernob outlets between 1979 and 1992.