Nicola Leone is an Italian computer scientist who works in the areas of artificial intelligence, knowledge representation and reasoning, and database theory.

[1] Leone is currently the rector of the University of Calabria and a professor of Computer Science.

[4] Leone has published more than 250 scientific articles in the areas of artificial intelligence, knowledge representation and reasoning, and database theory.

[5] In the area of artificial intelligence and knowledge representation and reasoning, he is best known for his influential early work on answer set programming (ASP) and for the development of DLV, a pioneering system for knowledge representation and reasoning, which was the very first successful attempt to fully support disjunction in the datalog language, achieving the possibility to compute problems of high complexity, up to NP

To the field of database theory he mainly contributed through the invention of hypertree decomposition, a framework for obtaining tractable structural classes of conjunctive queries, and a generalisation of the notion of tree decomposition from graph theory.