Costalpino is a village in Tuscany, central Italy, in the comune of Siena, province of Siena.

It is located about 5 km south-west of Siena. Renaissance painter Marco Pino was born in Costalpino in 1521.

• Emanuele Repetti (1841). "Costalpino". Dizionario geografico fisico storico della Toscana. Vol. 4. Florence. pp. 266–267.