Although there is a large amount of research examining the social behaviors of individuals with Williams syndrome (WS), the findings have not been extended to the development of interventions designed to directly address their social skills deficits. This paper presents the iterative process to develop a social skills training program that meets the unique needs of adults with WS. This paper adds to the literature in three ways. First, this paper extends previous research on children with WS by assessing the social skills deficits of a large sample of adults with WS. We provide data that indicate that, similar to children with WS, adults with WS continue to experience the most impairments related to social cognition and least impairments related to social motivation. Second, this paper uses the results of the social skills survey to talk with parents and adults with WS about their social needs and the needs on which they feel a social skills training program should focus. Finally, this paper is the first to develop a social skills intervention for individuals with WS. Borrowing from the methods and curricula for social skills training programs for individuals with autism, this paper reports on how lesson plans were adapted to meet the unique needs of individuals with WS. We present results from an initial pilot of four lesson plans developed for an intervention specific for adults with WS. These lesson plans meet a critical need to address the social skills deficits of adults with WS.