Callosciurus is a genus of squirrels referred to as the "beautiful squirrels". 

Rodentia is from Latin for rodens 'gnawing'.

Sciuridae: from Latin Sciurus which is from the Ancient Greek word σκίουρος (skiouros; from σκιᾱ́ ('shade') and οὐρᾱ́ ('tail')),referring to the long bushy tail which many of its members have.

The word squirrel comes from the Anglo-Norman esquirel which is from the Old French escureil, the reflex of a Latin word sciurus.

"Callosciurus" translates to "beautiful squirrels":
- Callo-: Derived from the Ancient Greek kallos (κάλλος), meaning beautiful.
- -sciurus: Derived from the Latin sciurus (borrowed from the Greek skiouros), meaning squirrel. Literally, skiouros is from skia (shadow) and oura (tail), referring to an animal that "sits in the shadow of its own tail."