A by-election for the Kladno Senate seat was held in the Czech Republic in March 2011. The first round was held on 18âÂÂ19 March while second was held on 25âÂÂ26 March 2011. It was held after death of incumbent senator Jià ÂàDienstbier. The election was won by his son Jià ÂàDienstbier Jr. who defeated Dan Jiránek.