Population characteristics and carapace growth rates were estimated for green turtles (Chelonia mydas) foraging in Arica Bay, northern Chile, from 2012 to 2016. Within the main foraging area of La Puntilla, an open population of up to 514 individuals was estimated by mark and recapture (Jolly-Seber method), with densities of 20–225 individuals/km². Captured individuals (n = 159) ranged from 44.6 to 98.6 cm straight carapace length (SCL) with a mean SCL of 64.9 cm (SD 10.8); most turtles were juveniles; however, 10 were adults with SCL > 80 cm (three of these being males). A mean body condition index (BCI) of 1.64 (range 0.34–3.63) indicated healthy population conditions, with mean annual growth rates (AGR) of 4.6 cm/year (SD 2.97). The consistent presence of turtles between 2012 and 2016 and the relatively high abundance compared to the general situation reported for the species in Chile makes Arica Bay the most important feeding congregation of green turtles in the country. The population's healthy state and size, its location within an urban radius, and the multiple human uses of this site represent aspects that must be considered in protection and development plans for the city's coastal border.