Carl Alexander Clerck (1709 – 22 July 1765) was a Swedish entomologist and arachnologist. Clerck came from a family in the petty nobility and entered the University of Uppsala in 1726. Little is known of his studies; although a contemporary of Linnaeus, it is unknown whether he had any contact with him during his time in Uppsala. His limited means forced him to leave university early and enter into government service, later ending up working in the administration of the City of Stockholm. Clerck's collection is in the Swedish Museum of Natural History.