The range will include men's and women's t-shirts and caps and goes on sale next month.
The 40-year-old music producer – who was nominated for an Oscar for his latest chart topping single – will also appear in the collection's television advert, with a track from his new album 'G I R L' providing the soundtrack.
The partnership will be a part of Uniqlo's UT t-shirt line, which is to receive a brand overhaul and be relaunched as The New Model T.
Pharrell's latest fashion project will be available in 14 different countries around the world, including the UK, from mid-April.
Uniqlo are currently said to be in talks to buy United States retailer J Crew in a deal which is estimated to be valued at $5 billion as founder Tadashi Yanai reportedly wants to turn his business into the world's largest clothing supplier.
