Andrzej Tadeusz Bonawentura Kościuszko (February 12, 1746 – October 15, 1817) is a Polish-Lithuanian and American general and military leader during the Kościuszko Uprising.

He is a national hero of Poland, Lithuania, the United States, and Belarus.

He leads the 1794 Kościuszko Uprising against Imperial Russia and the Kingdom of Prussia as Supreme Commander of the Polish National Armed Force (Najwyższy Naczelnik Siły Zbrojnej Narodowej).

Before commanding the 1794 Uprising, he fights in the American Revolutionary War as a colonel in the Continental Army.

In 1783, in recognition of his dedicated service, he is brevetted by the Continental Congress to the rank of brigadier general in a mass promotion given to all officers who had served during the war.

The United States also gives him a land grant.

On a visit to America in 1798, Kościuszko collects his back pay and entrusts it to his friend Thomas Jefferson in his will, directing him to spend the American money on freeing and educating black slaves, including Jefferson's.

Kościuszko dies in 1817, but Jefferson never carries out the terms of his will, nor does a friend to whom he transfers the executorship.

In 1852, Chief Justice Roger Taney of the U.S. Supreme Court transfers the money, by then worth more than $50,000, to Kościuszko's heirs in Poland, ruling that his American will had been invalid.

Several Anglicized spellings of Kościuszko's name appear in records.

Perhaps the most frequently occurring is Thaddeus Kosciusko, though the full "Andrew Thaddeus Bonaventure Kosciusko" is also seen.

In Lithuanian, Kościuszko's name is rendered as Tadas Kosciuška or Tadeušas Kosciuška.

In Belarusian, it is Tadevuš Kaściuška.