Vlatko Vuković Kosača (Serbian Cyrillic: Влатко Вуковић Косача; died ≈ sometime between August 1392 - August 1393) was a 14th-century Bosnian nobleman, Duke of Hum, Grand Duke of Bosnia (Serbo-Croatian: Veliki vojvoda bosanski) and one of the best military commanders of King Tvrtko I, for whom he governed Hum (part of modern-day Herzegovina), which was part of the Banate of Bosnia and later Kingdom of Bosnia. Vlatko was probably a son of duke Vuk Kosača, often regarded as founder of the Kosača noble family.