The density, surface tension, and viscosity of liquid Zr76.0−xFe24.0Nbx (x = 6.6, 10.0, 15.0) alloys were measured by using the electrostatic levitation technique. The maximum undercooling achieved for these alloys was 151, 91, and 119 K, respectively. To evaluate the thermophysical properties in a wider temperature range, molecular dynamics simulations were performed by using the embedded atom method potential. Both measured and simulated results indicate that the liquid density increases linearly with decreasing temperature and also gradually rises with increasing Nb content. Additionally, the simulated and experimental results for surface tension and viscosity were analyzed. In all three alloys, surface tension increases linearly with decreasing temperature. The relationship between viscosity and temperature follows an Arrhenius-type equation, with both surface tension and viscosity increasing as the Nb content increases. The calculated results of density, surface tension, and viscosity are in good agreement with the experimental results. Furthermore, the specific heat, emissivity, and diffusion coefficient of liquid alloys were calculated. The specific heat for liquid Zr76.0−xFe24.0Nbx (x = 6.6, 10.0, 15.0) alloys is (36.47 ± 1.68), (35.20 ± 2.28), and (41.04 ± 3.73) J mol−1 K−1, respectively. Emissivity decreases linearly with temperature. The diffusion coefficient decreases, while the diffusion activation energy increases with a higher Nb content.