The 18-year-old defeated 103 other women in the 56th edition of the beauty pageant.
The first runner-up Miss Romania Joana Valentina Boitor, 17. Miss Australia Sabrina Houssami, 20, came third.
Kucharova, a high-school student, became teary as she received her diamond crown from Miss World 2005, Unnur Birna Vilhjalmsdottir of Iceland.
India's entry Natasha Suri, 20, reached the semi-finals but could not go further.
Photograph: Getty Images