People with autism and other developmental disabilities are often supported by staff teams in accommodation, day support, and employment services. Although the literature outlines a number of individual staff characteristics that can influence the “quality of support,” there is a paucity of research investigating the characteristics of teams as a whole. Given the emphasis placed on “team work” in human services, this study investigated what constitutes the characteristics of an effective team in disability services. An online Delphi study was employed, whereby disability support staff and their managers answered a series of surveys to build a consensus as to “what constitutes an effective team.” The emerging consensus was analyzed using inductive thematic analysis, descriptive statistics, and the intraclass correlation coefficient. A consensus emerged concerning three core elements which combined constituted an effective staff team. In order of importance, these were a shared focus on client outcomes, effective leadership, and good communication among the team. However, a range of additional factors were also identified. These represented additional considerations that were, in the opinion of the participants, also important to building and maintaining an effective team. Focusing on client outcomes, fostering effective leadership, and ensuring good communication are necessary, but insufficient to establish an effective staff team. The implications are discussed in the context of policy development concerning staff recruitment, team development, supervision, and service evaluation.