The Gobiiformes (Wiley and Johnson, 2010) of the Americas comprise 308 species considered as valid in this chapter. An additional eight or more species are known and not currently described. Of the 308 species, 234 are in the family Gobiidae, 20 Microdesmidae, 4 Ptereleotridae, and 25 Eleotridae. Tables 2.1.1, 2.1.2, and 2.1.3 provide a list of all species in the Americas recognized herein. An initial species list was compiled using Catalog of Fishes (Eschmeyer, 2010), FishBase (Froese and Pauly, 2010), Shorefi shes of the Tropical Eastern Pacifi c (Robertson and Allen, 2008), and the Global Invasive Species Database (https://www.issg.org/database/ welcome/). Th at list was checked against the following fi eld guides and faunal lists: Navarro and Pequeño, 1979; Menezes and Figueiredo, 1985; Courtenay et al., 1986; Humann and Deloach, 1993; Cervigón, 1994; Grove and Lavenberg, 1997; Smith, 1997; De Moura et al., 1999; Th omson et al., 2000; Pezold and Cage, 2002; Floeter et al., 2003; Kullander, 2003; Menezes, 2003; Moura, et al., 2003; Moura and Menezes, 2003; Smith et al., 2003; and my database. Th e fi nal species tables were then reviewed by Carole Baldwin,