Kazimir is of Polish origin, meaning 'destroyer of peace'. It is derived from the Slavic elements kaziti, meaning 'to destroy', and miru, signifying 'peace'. Historically, Kazimir has been used primarily in Poland, where it was borne by several kings including Saint Casimir, the patron saint of Poland and Lithuania.
The name Kazimir experienced a significant increase in popularity from 2021 onwards, with a substantial jump to 17 births in 2021 and an unprecedented peak of 45 births in 2023. Prior to this recent surge, the name maintained relatively low but steady popularity between 1921 and 2020, with most years seeing fewer than 10 births annually.