The carolus was a gold coin struck in the reign of Charles I of England. It was originally valued at 20 shillings, but later 23. The name has also been used for other currencies bearing Carolus (Charles) as the name of the ruler, such as the Carolus dollar, a Spanish-American peso or piece of eight issued by Charles III (1759-88) and Charles IV (1788-1808) of Spain.
- This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed. (1728). "article name needed". Cyclopædia, or an Universal Dictionary of Arts and Sciences (first ed.). James and John Knapton, et al.
- "Carolus". Oxford English Dictionary. Oxford University Press. 2nd edition. 1989.