The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) is currently considering plausible models of the Southern Ocean ecosystem within the Working Group on Ecosystem Monitoring and Management (WG-EMM). While recognised to be an important component of this ecosystem, particularly with regard to food-web structure and function, squid have rarely been included in previous ecosystem models except perhaps to assess their potential impact as predators of Antarctic krill. This paper describes properties for three groups of squid that may be included in future ecosystem models of the Southern Ocean: onychoteuthids, ommastrephids and small – medium nektonic squids. Important ecological differences are considered to exist among these three groups (e.g. spatial and depth distribution, ontogenetic and vertical migrations). Furthermore, this paper reiterates findings from previous studies that squid should no longer be modelled as specialist predators on Antarctic krill.