This dataset was prepared to support a comparative descriptive analysis of municipal health expenditure across 14 megacities in low- and middle-income countries (LMICs). It compiles city-level population estimates and publicly reported fiscal figures for total annual expenditure and annual health expenditure, and derives two harmonised indicators: health expenditure as a share of total expenditure (%) and health expenditure per capita (USD per person). Financial data were extracted from official municipal, provincial/state, and national public finance documents and reports, with full traceable sources provided. Population estimates use UN DESA World Urbanization Prospects (urban agglomerations) and UN World Population Prospects. Currency conversions use IMF monthly average exchange rates for the relevant fiscal year.