Donato Maria Dell'Olio (Bisceglie, 27 December 1847 – Benevento, 18 January 1902) was an Italian cardinal and Catholic archbishop.

Dell'Olio studied at the seminary in Bisceglie and then at the Pontifical University of Saint Thomas Aquinas in Rome where his professors included the future cardinal Tommaso Maria Zigliara.

In Dell'Olio's speech at the inauguration of the institution, the cardinal said: I have sought from the beginning, an idea, almost a dream, a dream of those who love good and cannot reach it: But now, gentlemen, that which in the beginning seemed a dream, thanks to the beneficence of Leo XIII, whom the people of Benevento hold in the utmost esteem with every thought... is a solemn reality, and is before our eyes (and you are such a great part of it), that is, the Theological-Juridicial Institute in the augmented form of a Pontifical University.

The day has come, in which you gentlemen chosen to hold the professorial chairs and you dear young boys embarking on noble studies will enter the palaistra prepared for you, the one group to spread the doctrines of the science of divinity, the other to attain themPope Leo XIII raised Dell'Olio to the rank of cardinal in the Papal consistory of 15 April 1901 and he received the titular church of Santa Balbina.

On 16 June 1901 Dell'Olio was in Benevento to consecrate the Basilica della Madonna delle Grazie and its altar which was "a splendid gift from the munificence of Leo XIII."