The Kalmar Regiment (Swedish: Kalmar regemente), designations I 20, I 21 and Fo 18, was a Swedish Army infantry regiment that traced its origins back to the 16th century. It was merged with another unit to form a new regiment in 1928. It was later reraised and disbanded again in 1997. The regiment's soldiers were originally recruited from Kalmar County, and it was later garrisoned there.