A new species, Olixon atlanticus, is described from a secondary dry forest in Zambrano, Bolívar, Colombia. This species represents the second record of the genus from the Neotropical Region, and is close to O. banksii but can be distinguished by the length of the first flagellomere, the form of the premedian transverse carina of the first metasomal tergum, and by the presence of a weak median longitudinal impression on the second metasomal tergum that ends in a notch. Olixon atlanticus and O. testaceum are the first records of the genus for Colombia. An updated key to the species of Olixon is given. Also we record the genus and species Liosphex varius as new for Colombia.