Rosignano Marittimo is a comune (municipality) in the Province of Livorno in the Italian region Tuscany, located about 80 km southwest of Florence and about 20 km southeast of Livorno.
The municipality of Rosignano Marittimo contains the frazioni (subdivisions, mainly villages and hamlets) Castiglioncello, Rosignano Solvay, Vada, Castelnuovo della Misericordia, Gabbro, and Nibbiaia.
Rosignano Marittimo borders the following municipalities: Castellina Marittima, Cecina, Collesalvetti, Livorno, Orciano Pisano, Santa Luce.