Mairago is a comune (municipality) in the Province of Lodi in the Italian region Lombardy, located about 40 km southeast of Milan and about 7 km southeast of Lodi.
Mairago borders the following municipalities: Cavenago d'Adda, Turano Lodigiano, Ossago Lodigiano, Secugnago, Brembio.
The main economical activity is the cultivation of corn, barley and, to a lesser extent, wheat. Animal husbandry is also widespread, including beekeeping. Exploitation of methane reservoirs by AGIP is now virtually ended.