The Global Agenda 2030, widely known as the Sustainable Development GoalsSustainable development goals (SDGs), was adopted by United Nations (UN) member statesState in 2015 as a universal call to action to address the world’s most pressing challenges by 2030. Effective monitoringMonitoring and evaluationEvaluation (M&E) are essential for tracking progress, ensuring accountabilityAccountability, and informing policy decisions. This chapter examines the UN’s M&E system for the SDGs, with a focus on its implementation at the global, regional, and national levels. At the global level, the United Nations Statistical Commission and the Inter-agencyAgency and Expert Group on SDG Indicators (IAEG-SDGs) play key roles in data collection and reporting. Regionally, organisations such as ESCAP support data harmonisationData harmonization and regional assessments. At the national level, countries incorporate SDG indicators into their development plans, working through national statistical offices and collaborating with civil society. Voluntary National ReviewsVoluntary National Review (VNRs) provide an important platform for member statesState to report on their progress and share accomplishments. The discussion underscores the challenges and opportunities in achieving comprehensive, accurate, and timely evaluationsEvaluation. Notably, the Mid-Term Review in 2023 revealed a concerning rise in inequalityInequality amongst countries. By analysing the UN’s multi-tiered M&E framework alongside the Impact RankingImpact ranking System, this chapter outlines best practices and offers insights into future directions for understanding and addressing inequalityInequality.