COVID-19 imposed unprecedented financing requirements on countries to rapidly implement effective prevention and control measures while dealing with severe economic contraction. The challenges were particularly acute for the 11 countries in the WHO South-East Asia Region (SEAR), home to the lowest average level of public expenditure on health of all WHO regions. We conducted a narrative review of peer-reviewed, grey literature and publicly available sources to analyse the immediate health financing policies adopted by countries in the WHO SEAR in response to COVID-19 in the first 12 months of the pandemic, i.e. from 1 March 2020 to 1 March 2021. Our review focused on the readiness of health systems to address the financial challenges of COVID-19 in terms of revenue generation, financial protection and strategic purchasing including public financial management issues. Twenty peer-reviewed articles were included, and web searches identified media articles (n = 21), policy reports (n = 18) and blog entries (n = 5) from reputable sources. We found that countries in the SEAR demonstrated great flexibility in responding to the COVID-19 pandemic, including exploring various options for revenue raising, removing financial barriers to care and rapidly adapting purchasing arrangements. At the same time, the pandemic exposed pre-existing health financing policy weaknesses such as underinvestment, inadequate regulatory capacity of the private health sector and passive purchasing, which should give countries an impetus for reform towards more resilient health systems. Further monitoring and evaluation are needed to assess the long-term implications of policy responses on issues such as government capacity for debt servicing and fiscal space for health and how they protect progress towards the objectives of universal health coverage.