Mock interviews play a significant role in UPSC interview preparation by simulating the actual interview environment. They help candidates become comfortable with the format and types of questions they might face, promoting better performance. Feedback from mentors or peers during these sessions helps identify areas of improvement, such as body language, clarity of thought, and articulation. Furthermore, mock interviews assist in refining candidates' ability to discuss current affairs and personal experiences succinctly, which is critical for impressing the interview panel.