Somaglia (Lodigiano: ) is a comune (municipality) in the province of Lodi in the Italian region of Lombardy, located about southeast of Milan and about southeast of Lodi.
As of 31 December 2004, it had a population of 3,384 and an area of .
The municipality of Somaglia contains the frazione (subdivision) San Martino Pizzolano.
Somaglia borders the following municipalities: Casalpusterlengo, Codogno, Ospedaletto Lodigiano, Senna Lodigiana, Fombio, Calendasco, Guardamiglio.