One new species of Lomachaeta Mickel and 15 new species of Sphaeropthalma Blake are described from Central America and northern South America: L. garm sp. nov. from Colombia, S. alsvid sp. nov. from Costa Rica, Mexico, Honduras and Nicaragua, S. arvak sp. nov. from Mexico and Guatemala, S. chupacabra sp. nov. from Mexico, S. freki sp. nov. from French Guiana, S. geri sp. nov. from Colombia, S. gullinbursti sp. nov. from Mexico, S. gulltopp sp. nov. from Colombia, Trinidad, and Venezuela, S. hati sp. nov. from Mexico and Guatemala, S. hrimfaxi sp. nov. from Costa Rica, S. hugin sp. nov. from Colombia, S. munin sp. nov. from Colombia, S. nosferatu sp. nov. from Venezuela, S. ratatosk sp. nov. from Guatemala, S. skinfaxi sp. nov. from Mexico, and S. skoll sp. nov. from Costa Rica, Nicaragua, and Panama. A preliminary key to the male Sphaeropthalma of this region is provided. Two new species-groups are proposed for Neotropical Sphaeropthalma. A new distribution record is given for L. hyphantria Pitts & Manley. Male genitalia are illustrated for all male species.