瓦茨拉夫三世（捷克语：Václav III.、斯洛伐克语：Václav III.、德语：Wenzel III.、匈牙利语：Vencel、波兰语：Wacław、克罗地亚语：Vjenceslav III、塞尔维亚语：Вeнцeслав III, Venceslav III，1289年10月6日－1306年8月4日）最后一位普热米斯尔王朝的波希米亚国王（1305年-1306年在位）、匈牙利国王（1301年-1305年在位）及波兰国王（1301年-1306年在位）。瓦茨拉夫三世为最强大的捷克君主普热米斯尔·奥托卡二世之孙、瓦茨拉夫二世之子。

Wenceslaus III (Czech:Václav III., Hungarian:Vencel, Polish:Wacław, Slovak:Václav; 6 October 1289 –4 August 1306) was King of Hungary between 1301 and 1305, and King of Bohemia and Poland from 1305. He was the son of Wenceslaus II, King of Bohemia, who was later also crowned king of Poland, and Judith of Habsburg. Still a child, Wenceslaus was betrothed to Elizabeth, the sole daughter of Andrew III of Hungary. After Andrew III's death in early 1301, the majority of the Hungarian lords and prelates elected Wenceslaus king, although Pope Boniface VIII supported an other claimant, Charles Robert, a member of the royal house of the Kingdom of Naples.