The 1st Infantry Regiment "Sangarios" () is a motorized infantry regiment of the Hellenic Army. Established in 1885 at Athens, it fought in all conflicts in which Greece participated until World War II, when it was disbanded following the German invasion of Greece. It was re-established as the 21st Brigade (21η Ταξιαρχία) in 1945, and participated in the Greek Civil War. Receiving the designation 1st Infantry Regiment again in 1951, it was headquartered in Florina from 1952 until its disbandment in 1998. In 2013 it was re-established at Florina.
