Serbia's President Aleksandar Vucic nominated Brnabic as the conservative country's first openly gay prime minister, a move which infuriated nationalists.
Brnabic said today: "I'm proud and still too emotional from all of this."
Her government needs formal approval by Serbia's parliament next week for her to become the first female head of government in Serbia.
Brnabic's nomination is considered part of Vucic's tactics to please the West amid strong pressure from Moscow to maintain influence in the region and keep Serbia away from Western integration.