Aleksander Zasławski (died 1629) was a Polish-Lithuanian noble, voivode of Bracław (died 1628) and voivode of Kiev (1628–1629).
In 1620 he inherited much wealth from his relative, Janusz Ostrogski.
Son of Janusz Zasławski and Aleksandra Sanguszko. Married to Eufrozyna Ostrogska. Father of Władysław Dominik Zasławski, Franciszek Zasławski and Karol Zasławski.