The 30-year-old singer and actress - who has her own successful clothing and accessories ranges - will use her experience to mentor wannabe designers as they compete for a multi-million dollar contract.
No stranger to reality TV, Simpson has already starred in Newlyweds with her ex-husband Nick Lachey, and The Price Of Beauty, and Paul Telegdy, NBC and Universal Media Studios executive vice president, said he was 'delighted' to have secured her for the network's show.
'With an almost billion-dollar lifestyle brand under her belt she is sure to be an excellent mentor to our up-and-coming designers,' he said.
Supermodel-turned-business woman Elle Macpherson will host the programme.