Born 15 December 1986 in Severodonetsk, Onopka moved to the Ukrainian capital, Kyiv, in 2001. While there, she was spotted by a foreign scout at the age of 15 and thus began her career as a model. In 2005, Steven Meisel photographed Onopka for the Prada and Dolce & Gabbana fall ad campaigns, sparking a booking frenzy thereafter and he then photographed her for two covers of Italian Vogue.