Castellina Marittima is a comune (municipality) in the province of Pisa in the Italian region Tuscany, located about southwest of Florence and about southeast of Pisa.
The territory of Castellina Marittima borders the following municipalities: Cecina, Chianni, Riparbella, Rosignano Marittimo, Santa Luce.
For centuries Castellina has been an important source for alabaster.