|Comune di Oppido Mamertina|
|Province||Reggio Calabria (RC)|
|Frazioni||Castellace, Messignadi, Piminoro, Tresilico|
|• Mayor||Bruno Barillaro|
|• Total||58 km2 (22 sq mi)|
|Elevation||342 m (1,122 ft)|
|Population (December 2007)|
|• Density||95/km2 (240/sq mi)|
|Time zone||CET (UTC+1)|
|• Summer (DST)||CEST (UTC+2)|
|Saint day||25 March|
Oppido Mamertina (Greek-Calabrian dialect: Oppidù, Ofidus) is a town and comune of the province of Reggio Calabria in Calabria in southern Italy at about 62 kilometres (39 mi) northeast of Reggio Calabria and about 120 kilometres (75 mi) southwest of Catanzaro.
It is the seat of the Diocese of Oppido Mamertina.
The municipality includes the following boroughs (frazioni): Castellace, Messignadi, Piminoro, and Tresilico.
The ancient history of the town is largely unknown, but archeological excavations in Mella might point its origins to the mythical Mamerto (3rd century BC – 1st century AD). The first mention of the town (Oppidum in Latin, meaning citadel) is 1040, during the Byzantine Era.
On February 5, 1783, an earthquake completely destroyed the town killing 1,198 people. The town was rebuilt near the neighbouring village Tresilico (incorporated in the municipality in 1927). Other earthquakes hit the town in 1894 and on December 28, 1908, which destroyed the neighbouring township Castellace.
The town is home to the 'Ndrangheta, a Mafia-type criminal organization based in Calabria. Several powerful criminal clans originate from the town, such as the Mammoliti-Rugolo. The town achieved a sad notoriety in July 2014 when, two weeks after Pope Francis, visiting Calabria, had publically excommunicated the Mafia, a procession carrying a statue of the Madonna stopped to pay homage outside the house of an home confined local mafia leader. 
- Saverio Mammoliti (born 1942), 'Ndrangheta boss
- Candido Zerbi (1827–1889), politician and senator
- Alessio Viola
- All demographics and other statistics from the Italian statistical institute (Istat)
- Oppido Mamertina: Tour in City
- Faulting and earthquake triggering during the 1783 Calabria seismic sequence, Jacques E., Monaco C., Tapponnier P., Tortorici L. & Winter T., Geophysical Journal International, Volume 147, Number 3, 2002, pp.499-516
- Woman of honour, The Independent, February 25, 1996