Public speaking holds significant importance in UPSC interview preparation as it enhances communication skills and builds confidence. Effective articulation of thoughts during the interview can create a positive impression on the board. Practicing through mock interviews and engaging in group discussions improves fluency, clarity, and conviction in responses. Additionally, public speaking helps aspirants learn to manage anxiety and respond to unexpected questions with poise. Developing an ability to communicate complex ideas simply is crucial, as it directly correlates with the ability to express oneself effectively in any interview scenario.