| Sant'Alessio Siculo | |
| Official Name: | Comune di Sant'Alessio Siculo |
| Coordinates: | 37.9167°N 36°W |
| Region: | Sicily |
| Metropolitan City: | Messina (ME) |
| Frazioni: | Lacco |
| Mayor: | Domenico Aliberti |
| Area Total Km2: | 6.17 |
| Population Footnotes: | [1] |
| Population Total: | 1519 |
| Population As Of: | 30 November 2021 |
| Population Demonym: | Santalessesi |
| Elevation M: | 15 |
| Saint: | Madonna del Carmine |
| Day: | July 16 |
| Postal Code: | 98030 |
| Area Code: | 0942 |
Sant'Alessio Siculo (Sicilian: Sant'Alessiu Sìculu) is a comune (municipality) in the Metropolitan City of Messina in the Italian region Sicily, located about 180km (110miles) east of Palermo and about 35km (22miles) southwest of Messina.
Its main attraction is a castle built in the 11th century by the Byzantine emperor Alexios I Comnenos in his war against the Normans and the Arabs, who also held it. It sits on the promontory Capo Sant'Alessio overlooking the sea and beach.