The transition to college is a critical period marked by various academic, social, and emotional challenges for first-year students. This chapter explores the development and application of the Student Adaptation to College Questionnaire (SACQ), a comprehensive tool designed to assess these multifaceted aspects of student adjustment. The SACQ comprises 67 items across four subscales: Academic Adjustment (24 items), Social Adjustment (20 items), Personal-Emotional Adjustment (15 items), and Institutional Attachment (15 items). It has been extensively used to measure the adaptation process in diverse cultural contexts. This chapter provides an overview of the SACQ’s creation and reviews the translations of the SACQ into multiple languages, highlighting adaptations for cultural relevance and psychometric robustness. The psychometric properties of the SACQ, including internal consistency, test-retest reliability, construct validity, criterion validity, and predictive validity, are discussed in detail. This chapter also addresses the limitations of the SACQ, particularly the need for updates to reflect contemporary changes in student life, such as the rise of online learning and social media use. Finally, recommendations for future research include developing new subscales to assess digital learning environments and digital social interactions among students. The SACQ continues to be an important tool for understanding and supporting college students’ adaptation, but it needs to be periodically revised to maintain its relevance in an evolving educational environment.