The present study investigated the well-being of student veterans and service members (SVSMs), a rapidly-growing subpopulation of college students in the U.S. with unique needs and lived experiences, through the lens of Self-Determination Theory (SDT). SDT posits that contextual factors relate to well-being via perceived satisfaction of three basic psychological needs (i.e., competence, autonomy, and relatedness) and the facilitation of intrinsic motivation. A path model tested these SDT-stipulated relations in a sample of 182 SVSMs from the three Regent universities in Iowa, incorporating four SVSM-specific contextual factors (i.e., Office of veterans and military services (OVMS) support, veteran-friendly campus perception, veteran identity centrality, and positive regard for veteran identity). The model yielded a good fit; however, not all of the hypothesized relations were significant. Veteran-friendly campus perception and positive regard for veteran identity emerged as robust direct predictors of psychological need satisfaction and indirect predictors of well-being (i.e., globally and specific to the academic domain). OVMS support had a significant relationship only with perceived relatedness, and veteran identity centrality did not have significant direct or indirect relations with any of the psychological needs or well-being. Perceived competence was a robust mediator of multiple relations between contextual factors and well-being, and perceived relatedness also mediated some of the relations between contextual factors and well-being. The predictive utility of volitional autonomy and academic intrinsic motivation was not supported in the present study. Conclusions, implications, and future directions for research are discussed.