Prince Eustachy Stanisław Sanguszko (28 August 1842 – 2 April 1903) was a Polish noble (szlachcic) and conservative politician.

He sympathized with the insurgents of the January Uprising of 1863–1864 and took part in meetings in Goszcz.

In April 1863 he traveled with a secret correspondence for the "Hôtel Lambert" to Paris, and stayed there until the end of the Uprising.

Successor of Kazimierz Feliks Badeni in the office of governor of Galicia from 1895 until 1898.

So Prince Eustachy Stanisław Sanguszko is a 5th generation uncle of Queen Mathilde of Belgium.