Lippia L. is the largest genus in Verbenaceae, with ca. 140 species distributed mainly in temperate and tropical South America and the Caribbean, and some lineages in Africa and Asia. A complete taxonomic revision of Lippia in Paraguay is here provided, based on the study of almost 700 herbarium specimens. As a result, 27 taxa, 25 species (two endemic), and two varieties are here recognized. A key for species identification is provided, plus detailed morphological descriptions, illustrations, photographs, updated synonymy with eight new synonyms, discussion about the relationships among closely related taxa, notes on geographic distribution and ecology, distribution maps, and a list of selected specimens analyzed. Fifteen lectotypes are designated for Lantana aristata Schauer var. brachypoda Briq., Lantana aristata (Schauer) Briq. var. latiuscula Briq., Lippia aristata Schauer f. pluripedunculata Kuntze, Lippia balansae Briq., Lippia calliclada Briq., Lippia citrata Cham., Lippia globiflora (L'Hér.) Kuntze f. lilacina Kuntze, Lippia gracilis Schauer, Lippia heterophylla Briq. var. ciliatifolia Briq., Lippia lasiocalycina Cham., Lippia recolletae Morong, Lippia tegulifera Briq. var. parvifolia Briq., Lippia turnerifolia Cham. var. camporum Griseb., Lippia villafloridana Kuntze, and Verbena globiflora L'Hér. Four second-step lectotypes are designated for Lippia lupulina Cham., Lippia morongii Kuntze, Lippia obscura Briq., and Lippia phryxocalyx Briq.