Internal void defects as shrinkage porosity, gas bubble, and thermo-mechanical cracks are usually formed during steel casting processes. These defects have critical impact on the quality and service life of hot-rolled products. Study of the possibility of self-healing of existing internal defects during hot-rolling process has been of interest to industry and researchers. Prediction of void closure is extremely useful in relation to better product design and manufacturing process optimization. Herein, a 3D finite element model of the slab hot-rolling process is developed to simulate and analyze the healing of internal voids in hot-rolled steel plate. The material model for the steel plate is developed based on Johnson–Cook constitutive relation to accurately represent its viscoplastic behavior at high temperatures as well as account for strain rate sensitivity. The study evaluates the thermal and mechanical response of low-carbon steel slabs having pre-existing voids during multi-pass strands reverse hot-rolling process. Through thickness plastic strains within the slab are found to influence void closure. Results show that variation in void size and locations also affect the healing possibilities. Finally, the effect of thermal history and thermo-mechanical stresses on void closure is studied.