Applying a unifying theoretical framework of high‐quality work relationships, we conducted a set of 3 complementary studies that examined whether high‐quality mentoring relationships can buffer employees from the negative effects of ambient discrimination at work. Integrating relational mentoring with relational systems theory, we first examined whether the presence of a high‐quality mentoring relationship buffers employees in a sample of 3,813 workers. In support of the “mentors‐as‐buffers” hypothesis, we found that employees who witnessed or were aware of racial discrimination at work had lower organizational commitment than those not exposed, but employees with high‐quality mentoring relationships experienced less loss of commitment than those lacking mentors. We then examined the specific buffering behaviors used by mentors in high‐quality relationships and whether these behaviors were effective for other work relationships and outcomes. Applying Kahn's typology, we developed and validated a measure of high‐quality relational holding behaviors in a sample of 262 workers. Using this measure in a third sample of 557 workers, we found that mentors buffer by providing holding behaviors, but we did not find this buffering effect when supervisors or coworkers provided holding behaviors. This potent mentor buffering effect held across a range of outcomes, including organizational commitment, physical symptoms of stress, insomnia, and stress‐related absenteeism. These studies suggest that mentoring may be a singularly effective relationship that offers a safe harbor for employees faced with ambient discrimination at work.