Italian linguist who pioneered in dialect studies, emphasized the importance of studying living vernaculars, and prepared a model classification of Italian dialects.

Ascoli did not receive any formal higher education, but he wrote his first major work, on Oriental languages, in 1854. While serving as a professor at the University of Milan (1860–1907), he made notable contributions to comparative linguistics, including Celtic, but his main work was in dialectology. In 1873 he founded the journal Archivio glottologico italiano (“Italian Linguistic Archives”), which he edited until 1907. In the first volume he published an essay on neglected Raeto-Romanic dialects and in the eighth his classification of Italian dialects.