Academic integrity is a foundational principle of higher education, ensuring fairness, trust, and credibility in teaching, learning, and assessment. However, rapid transformations in assessment practices—driven by digitalization, online learning, and artificial intelligence—have intensified challenges related to academic misconduct. This paper examines the evolving landscape of academic integrity and assessment challenges in higher education. Drawing on an extensive review of academic literature, policy documents, and international best practices, the study explores key integrity issues such as plagiarism, contract cheating, assessment security, and AI-assisted misconduct. The paper analyzes how traditional assessment models are increasingly strained under contemporary learning environments and proposes a comprehensive framework for promoting academic integrity through assessment redesign, institutional policies, and ethical pedagogy. The study concludes that sustainable academic integrity requires a shift from punitive approaches toward educative, transparent, and competency-based assessment strategies.