Universal health coverage (UHC) is one of the targets within the Sustainable Development Goals that the Member States of the United Nations have pledged to achieve by 2030. Target 3.8 has two monitoring indicators: 3.8.1 for coverage of essential health services, for which a compound index from 16 tracer indicators has recently been developed; and 3.8.2 for catastrophic expenditure on health. The global baseline monitoring of these two indicators in 2017 shows that the progress in many low- and middle-income countries is unlikely to be on track and achieved by 2030. The monitoring and evaluation mechanism for UHC progress is a crucial function to hold governments accountable and guide countries along their paths towards UHC. This paper outlines key monitoring and evaluation tools that Thailand uses to track UHC progress; compares the strengths and limitations of each tool; and discusses monitoring gaps and enabling factors related to development of the tools. Thailand uses several data sources to monitor three UHC dimensions: population coverage; service coverage; and financial risk protection. The four key sources are: (i) national surveys; (ii) health facility and administrative data; (iii) specific disease registries; and (iv) research. Each source provides different advantages and is used concurrently to complement the others. Despite initially being developed to track progress for national health priorities, these tools are able to monitor most of the global UHC indicators. Key enabling factors of Thai monitoring systems are a supportive infrastructure and information system; a policy requirement for routine patient data records; ownership and commitment of the key responsible organizations; multisectoral collaboration; and sustainable in-country capacities. The areas for improvement are monitoring in the non-Thai population; tracking access to essential medicines; and maximizing the use of collected data. Lessons learnt from the Thai experience could be useful for other low- and middle-income countries in developing their UHC monitoring platforms.