This paper offers a taxonomic treatment of the New World species of the Holarctic genus Chrysomela L. Twenty-one species and subspecies are recognized, of which ten, from the United States, Canada, and Alaska, are described as new. Three forms that have been considered varieties are recognized as species, and one specific and four varietal names are suppressed. Two new names are proposed for homonyms. Two species that were described in Chrysolina Mots. are transferred to Chrysomela and one described in Lina Redt. (= Chrysomela L.) is transferred to Microtheca Stål. Confusion of American species with one another and with the Eurasian species tremula Fab., saliceti (Ws.). and lapponica L. is noted.