Alessandro Fancellu (born 24 April 2000) is an Italian cyclist who currently rides for UCI ProTeam Q36.5 Pro Cycling Team. Fancellu previously rode for Kometa Xstra Cycling Team, where he was promoted to the senior team in 2020 after a year with their under-23 development side.

In the junior men's road race at the 2018 UCI Road World Championships, Fancellu finished over a minute and a half behind runaway winner Remco Evenepoel but managed to outsprint Alexandre Balmer to take the bronze medal. In 2020, from 1 August until the end of the year, Fancellu joined UCI WorldTeam Trek–Segafredo as a stagiaire.