Saint-Galmier (French pronunciation: [sɛ̃ ɡalmje]) is a city in eastern France. It is a commune in Loire department, and belongs to the arrondissement of Montbrison. Saint-Galmier covers an area of 19.5 square kilometers. As of January 1, 2018, it had a population of 5,737, ranking 1,903th among French communes. Saint-Galmier, located on the river Coise, south-central Loire, is a regional central city known for the mineral water Badoit produced there.