Caison is a modern American spelling of Cason, an English surname of uncertain origin that is usually explained as "son of Cass", from a medieval short form of names like Cassandra, or as a respelling of Case. It arrived in the wake of Jaxson and Grayson, with the -ai- spelling of Kaison and Kaiden. Caison peaked at number 1940 in 2022, has not reached the US top 1000 and ranks number 2307 in 2025.