and accessible to drive innovation and guide decision- making by food system actors and across all food system activities, components, sectors, policies, and outcome areas (Nguyen 2018). • Sustainable food systems transformation demands timely, high-quality, and reliable data and analytics that span the entire food system to: • (1) inform adaptation of food system activities by food system actors; • (2) guide shared agendas, goals, and performance indicators around food systems; • (3) enable evidence-based design, coherence, coordination, implementation, assessment, and reform of food system policies; and • (4) guide review, dialogue, learning, monitoring, mutual accountability processes, and performance assessments of the transformation, including progress toward attaining desired outcomes. • However, the extent of data availability and gaps in data to inform food systems transformation remains an understudied area • Against this background, this chapter seeks to • (1) highlight the importance of timely and high-quality data for food systems transformation; • (2) examine the main data needs for food systems transformation; • (3) assess selected current data efforts in relation to food systems transformation needs; • (4) highlight data gaps, challenges, and opportunities in relation to food systems transformation; and • (5) provide recommendations for closing data gaps, addressing challenges, and harnessing opportunities in order to improve data for decision-making in food systems transformation.