Count Stefano Jacini (Casalbuttano, 20 June 1826 – Milan, 15 March 1891) was an Italian statesman and economist.

For his work on La Proprietà fondiaria in Lombardia (Milan, 1856) he received a prize from the Milanese Società d'incoraggiamento di scienze e lettere and was made a member of the Istituto Lombardo.

In another work, Sulle condizioni economiche della Valtellina (Milan, 1858, translated into English by W. E. Gladstone), he exposed the evils of Austrian rule, and he drew up a report on the general conditions of Lombardy and Venetia for Cavour.

He was instrumental in bringing about the alliance with Prussia for the war of 1866 against Austria, and in the organization of the Italian railways.

From 1881 to 1886 he was president of the commission to inquire into the agricultural conditions of Italy, and edited the voluminous report on the subject.