Prince Eustachy Erazm Sanguszko (1768–1844) was a Polish nobleman, general, military commander, diplomat and politician.

In the years 1780–1786, Sanguszko graduated from the military school of Strasbourg and served in the Régiment Royal-Allemand (together with Stanisław Mokronowski) of the French Royal army.

On 3 February 1789, Sanguszko began service in the Crown Army as a captain in the 8th National Cavalry Brigade [pl].

[2] Sanguszko partook in the War of the Second Partition where he fought at the Battle of Zieleńce as a cavalry brigadier, receiving the Virtuti Militari in its wake on 23 June.

To protect family land holdings in Ukraine, Sanguszko refused to participate in Prince Poniatowski's 1813 campaign, for which the commander-in-chief, an old friend, punished him harshly with a dishonourable discharge from the army.