The singer was in the capital city to unveil the sexy collection, created for clothing chain River Island, which echoes her own raunchy style.
Models paraded through a tiered runway in midriff-baring crop tops, thigh high boots and sheer monochrome dresses as hip-hop music blared at the Rihanna for River Island show.
Speaking to reporters at the event, Rihanna said: "My first Fashion Week in London is my show. That's amazing."
At the end of the showcase, the We Found Love hitmaker emerged to take a bow, and later celebrated her debut with a night out on the town with British model Cara Delevingne in Soho nightclub The Box.
Rihanna's line will be sold at River Island stores from next month.