In this article, thermal modeling of a single basin solar still coupled with an evacuated tube solar collector under natural circulation mode has been carried out on the basis energy balance equations. The expressions of inner surface of glass cover, outer surface of glass cover, basin liner, and water mass have been derived for the numerical computation. The experiments were conducted under various meteorological conditions for 0.05 m water depth. This experimental setup has been installed at Solar Energy Park, Tamilnadu College of Engineering, Coimbatore, India (Latitude: 11 degrees N; Longitude: 77 degrees E; and an altitude of 409 m above sea level). Observation revealed that there was a considerable increase in the average daily yield of solar still when integrated with an evacuated tube solar collector. For all the cases, the correlation of coefficients (r) between theoretical and experimental values have been verified and they showed good agreement with 0.98 < r < 0.99 and root mean square present deviation of 10.26 < e < 39.7%.