Gender diversity in Science, Technology, Engineering, and Mathematics (STEM) fields remains a critical issue worldwide. Women and underrepresented gender groups continue to face barriers in STEM education and careers, impacting innovation, productivity, and social equity. This paper explores the barriers to gender diversity in STEM, including societal biases, institutional discrimination, and workplace challenges. Additionally, it examines strategies for promoting inclusion, such as policy reforms, mentorship programs, and organizational initiatives. By analyzing existing research and case studies, this paper provides comprehensive insights into how gender diversity in STEM can be improved to foster a more equitable and innovative future.