Abstract The Hangai Dome in central Mongolia represents one of the most prominent intracontinental uplifts, yet the relative contributions of crustal and mantle dynamics in sustaining its high topography remain unresolved. Here we jointly invert Rayleigh wave dispersion and receiver function data to constrain crustal and uppermost mantle structures, including Moho and lithosphere‐asthenosphere boundary (LAB) architecture, crustal Vp/Vs ratios and Vs. Our results reveal the significantly thickened crust (50–53 km) and thinned lithosphere (65–70 km) beneath the Hangai Dome, with pronounced lateral variations indicating presence of fluids and volatiles in the lower crust beneath the eastern Hangai Dome that generates low‐velocity zone and promotes rapid ascent of mantle‐derived melts. Furthermore, surface elevation exhibits strong linear correlations with crustal thickness and Bouguer gravity anomalies, consistent with near‐isostatic equilibrium. Our results indicate a leading role of inherited thickened crust in controlling topographic uplift of the Hangai Dome, whereas asthenospheric upwelling likely exerts a secondary influence.