Contrary to previous literature concluding that body size of Canis latrans (coyotes) does not increase in North America with decreasing longitude, this study presents data from different regions and concludes that northeastern coyotes are the largest extant version of coyote. Male coyotes from northeastern North America (16.4 ± 1.5 [SD] kg, range = 14.2–20.4) were heavier than females from the northeast (14.7 ± 1.6 kg, range = 11.9–17.9) and were also heavier than male (10.6 ± 1.0 kg, range = 8.8–12.0) and female coyotes (12.1 ± 1.1 kg, range = 10.5–14.1) from outside of the northeast. Female coyotes from northeastern North America were heavier than all male and female western coyotes. Longitude was significantly correlated in both male (r = − 0.786, P < 0.0001) and female (r = − 0.769, P < 0.0001) body mass, whereas there was less of a correlation for latitude and body mass for males (r = 0.355, P = 0.043) and females (r = 0.364, P = 0.044). Sixty-two percent (P < 0.0001) and 59% (P < 0.0001) of variation in body mass of males and females, respectively, could be explained by longitude, while 13% (P = 0.043 for males; P = 0.044 for females) could be accounted for by latitude.