Research self-efficacy represents the adaptation of the social cognitive concept of self-efficacy to the field of academic and scientific research and is one of the best predictors of successfully engaging in research activities. The current meta-analysis focuses on the relationship between research self-efficacy and 14 other relevant variables suggested by Social Cognitive Career Theory and analyzes 85 published and unpublished studies conducted between 1989 and 2020 (n = 17,754, 209 effect sizes). The results indicate large associations between research self-efficacy and interest in research, research identity, intention/goals to pursue a career in research, research productivity, attitudes toward research, research training environment, and working alliance with the advisor, moderate associations with research outcome expectations, Holland's investigative interests, research anxiety, and research mentoring experiences, as well as a small association with year in doctoral studies. There is no significant relationship between research self-efficacy and two other variables, gender and age of participants. Our findings help educators by showing ways through which to increase research self-efficacy in order to improve research training and career outcomes; the results suggest that effective routes for educators are the selection of students who have investigative vocational interests, an active control of possible research anxieties, development of a strong research-oriented culture in the research group and the development of a mentoring and transformational relationship with their trainees.