Born in Athens to an interior-designer mother and a textile-engineer father, Katrantzou moved to the US to study architecture at Rhode Island School of Design before transferring to Central Saint Martins, completing her BA in 2005 and MA in 2008. She switched her focus from interior prints to fashion prints, and her first ready-to-wear collection debuted at London Fashion Week in 2009 — a small nine-dress collection that still picked up 15 stockists.
Her collections are sold in over 200 shops across 47 countries, including Selfridges, Harvey Nichols, Neiman Marcus and Net-a-Porter. She has collaborated with Longchamp, Topshop and Adidas, won the Swiss Textiles Award (2010) and the BFC/Vogue Designer Fashion Fund (2015), and in April 2024 became Bulgari's first creative director for leather goods and accessories.