Organizational leaders in defence and security are investing in diversity and inclusionDiversity and Inclusion policies, strategies, and programs to help establish a culture of belongingCulture of belonging by embracing and leveraging personnel’s diverse backgrounds, including their knowledge, skills, talents, lived experiences, cultural perspectives, and worldviews. By focusing on collective approaches that enable effective teamTeams-based work environments, people within organizations experience greater meaning and purpose, focus on opportunities for learning and knowledge-sharing through open communication, advance creativity and innovation, establish effective social interrelationships and interdependencies, foster collective decision-making capabilities, and contribute to meaningful and impactful work products and outcomes. A teamTeams-based approach to diversity and inclusionDiversity and Inclusion in defence and security work environments can contribute to optimal performance, social cohesionCohesion, mutual trust and respect, critical thinking and problem-solving, and creativity and innovation. This chapter introduces teamTeams diversity and inclusionDiversity and Inclusion in defence and security and provides a brief overview of the chapters presented in this book, including the multidisciplinary perspectives to advance our knowledge in teamTeams-based diversity and inclusionDiversity and Inclusion policies, strategies, programs, and practices to drive sustainable culture changeCulture change. Topical areas focus on genderGender andEthnic diversity ethnic diversity and inclusionDiversity and Inclusion, unprofessional conductUnprofessional conduct (e.g., sexual misconductSexual misconduct and racismRacism), evidenced-based diversityDiversity, (inclusive and transformational) leadershipLeadership, and future strategies and recommendationsStrategies and Recommendations that examine the potential impacts and opportunities for enabling diverse and inclusive teamTeams-based organizations (e.g., mentoring programs, cross-cultural competence, and allyshipAllyship). Supporting equityEquity, diversityDiversity, and inclusionInclusion in defence and security-based work environments is tantamount to fostering a culture of belongingCulture of belonging and professional growth where everyone contributes to the collective mission, goals, and well-being of the organization.