Ortonovo is a frazione (borough) in the comune of Luni in the Province of La Spezia, Liguria, north-western Italy. It is located about southeast of Genoa and about east of La Spezia.
Until April 2017 it was the name of the commune including both Ortonovo and Luni.
The ancient town is surrounded by a line of walls with two entrances. In the central square is the Guinigi Tower, today the campanile of the church of St. Lawrence (17th century) but once connected to a now disappeared castle. Other sights include: