The regiment was founded on 20 June 1919. According to some, the regiment's date of establishment is considered to be 5 December 1918, when the order approving the formation of the
2nd Infantry Regiment was issued, as the 6th Regiment was formed from the 2nd Regiment's 1st Battalion. The regiment's soldiers fought against the
Red Army from January to June in 1919: at
Jieznas (February 10–13),
Žiežmariai,
Subačius. In June, the battalion was renamed to the
Separate Marijampolė Battalion. In 1939, the 6th Infantry Regiment had two battalions, totalling 1,300 soldiers. In the flag given to the regiment in 1937, the inscription was "Tau, tėvų žeme" (For you, the Land of my Fathers). In 1939 March, after the German occupation of the
Klaipėda region, the regiment moved to
Plungė, while its 2nd Battalion was deployed in
Telšiai. It was part of the
3rd Infantry Division. == Regiment commanders ==