Tvrdonice is a village and municipality (obec) in Břeclav District in the South Moravian Region of the Czech Republic. The municipality covers an area of 21.15 square kilometres (8.17 sq mi), and has a population of 2,046 (as at 28 August 2006). Tvrdonice lies approximately 8 kilometres (5 mi) east of Břeclav, 56 km (35 mi) south-east of Brno, and 238 km (148 mi) south-east of Prague.