The study examined the development of speech-language pathology (SLP) trainee clinical self-efficacy (CSE)-defined as an individual's confidence in performing tasks related to speech and language assessment and intervention-over the course of graduate clinical training. The study also examined the relationship between preprogram experience and CSE as well as the relationship between trainee self-efficacy and clinical performance. Participants, two cohorts of full-time SLP graduate trainees (N = 75), completed a novel SLP-specific measure of CSE at the beginning, middle, and end of a 2-year master's program and provided background information and access to practicum evaluations. CSE increased significantly at each point of assessment (p < .001). Students reported lower levels of self-efficacy for tasks related to evaluation compared to administration/report writing, collaboration, communication, and counseling (p < .001). Results also showed lower levels of intervention-related CSE compared to collaboration (p < .001) communication and counseling (p < .05). The variability in task-specific confidence decreased as training progressed; however, students' confidence in their evaluation skills continued to be lower relative to administration/report writing (p < .05) and collaboration (p < .01). Participants' prior clinical experience and preprogram training did not predict CSE; however, trainees with an undergraduate Communication Disorders (CD) major reported greater end-of-program self-efficacy than non-CD majors (p < .05). Trainee CSE was not found to be related to instructors' assessment of clinical performance. Findings provided preliminary insights into the nature and development of SLP-specific CSE over the course of graduate training and point to the potential pedagogical value of further examining factors associated with graduate trainee CSE in the context of clinical education.