Public speaking skills, the ability to address large audiences and interact with individuals, are crucial in social life. This chapter presents two studies on applying virtual reality (VR) technologies to public speaking training and support. The first study investigates the use of VR for reflection on public speaking training. Commonly, individuals record and review their presentations to identify areas for improvement. However, reviewing one’s own videos can cause discomfort and hinder objective self-assessment. To address this issue, the study confirmed the effectiveness of employing an avatar with a different appearance and using VR to review presentations from the audience’s perspective [38]. The second study examines the provision of real-time feedback in a VR environment. In VR, comprehensive data, including body movements, gaze, speech, and slide manipulation, can be utilized to detect issues and provide immediate feedback. However, due to the cognitive demands of the presentation, users may not always accept feedback. To alleviate this problem, the possibility of estimating feedback timing that is inappropriate for the user from observable information was investigated [8].