Many colleges and universities aim to address the STEM pipeline by focusing on introductory STEM gateway courses—with the objective of making them more attractive and stoking students’ interest in enrolling in these courses. However, students’ anticipated experiences with professors in these courses may prevent students from becoming interested in these courses in the first place. In the current research, three experiments examined how STEM professors’ fixed (vs. growth) mindset beliefs (i.e., beliefs that intelligence is fixed and unchangeable vs. malleable and developed) shape students’ anticipated psychological experiences in these courses (i.e., their expectations for fair treatment, sense of belonging, evaluation concerns), their anticipated course performance, and ultimately, their interest in taking the STEM professors’ courses. Results reveal that students anticipate more negative psychological experiences, lower performance, and report less interest in enrolling in STEM courses taught by professors who endorse fixed (vs. growth) mindset beliefs; however, these effects were moderated by student gender such that the effects of faculty mindset across all studies and outcomes were 22–74% larger among female students. Results suggest that professors’ growth mindsets may serve as a productive lever for increasing interest in STEM courses among college students—and especially among women.