For undergraduate nursing students, an integral mode of learning is their clinical placements. Learning within the clinical setting is influenced by factors such as the facilitators, peers, unit, or department the student is placed on. What is not known is the role of a social context that is grounded in Self-Determination Theory and how this influences the development of therapeutic relationship skills among undergraduate nursing students. The aim of this study was to examine the role of autonomy support in the professional learning of undergraduate nursing students. This study employed a two-group pre-test and post-test design, with undergraduate nursing students placed in either an autonomy-supportive group or a comparison group in an Australian context. Therapeutic relationship skills were assessed at the beginning and end of their compulsory mental health clinical placement. Participants were 210 (n = 210) Australian undergraduate nursing students. Using a tertile split, 140 students were placed into one of two groups based on their perception of autonomy support at the post-test time point. Pre- and post-test therapeutic relationship data were collected for both groups. A repeated measures analysis of variance was used to examine whether engagement in different clinical placements would illicit significant differences in therapeutic relationship skills. Undergraduate nursing students who were engaged in the autonomy-supportive setting had significantly higher scores associated with the therapeutic relationship subscales: Positive Collaboration and Positive Clinical Input. The importance of the social context is underscored, which is strongly influenced by the educational leader, typically referred to as a nurse facilitator.