Public speaking plays a vital role in preparing for the UPSC interview as it enhances communication skills and builds confidence. Aspirants must articulate their thoughts clearly, as interviewers are keen to assess personality and opinions. Engaging in public speaking practices helps candidates learn to frame answers succinctly and handle unexpected questions with poise. Practicing with peers or in front of a mirror can simulate real interview situations, reducing anxiety. Additionally, understanding body language and maintaining eye contact during mock interviews can significantly impact performance, helping candidates present themselves effectively.