Guglielmo Aretini-Sillani

Guglielmo Aretini-Sillani (18 August 1786 – 12 August 1875) was an Italian Roman Catholic bishop.

Ordained to the priesthood on 12 June 1813, Aretini-Sillani was named bishop of the Roman Catholic Diocese of Terracina, Priverno e Sezze, Italy in April 1835 and resigned on 4 December 1853.