Carolus may refer to:
People Carolus (name) the medieval Latin form of the name Charles Charlemagne (742–814) King Charles XII of Sweden, who is sometimes referred to as "Carolus Rex"
Scientific Carolus (plant), a genus of flowering plants in the family Malpighiaceae Carolus (planthopper), a genus of insects in the family Cixiidae 16951 Carolus Quartus, an asteroid named after Charles IV, Holy Roman Emperor
Miscellaneous Carolus (coin), several coins Carolus, several ships; see List of Swedish ships of the line
See also Carl (name) Charles Karl (disambiguation)