Thermal Physics is an advanced undergraduate course. It connects the world of everyday systems, of astronomical objects, and of chemical and biological processes with the world of molecular, atomic, and electronics systems. The course will be introduced through a unified approach to the equilibrium thermal properties of large systems based on the quantum viewpoint and statistical probability. The laws of thermodynamics and the concepts of entropy, temperature, chemical potential, free energy, and thermodynamic potential will be covered. The heat transfer, phase transition, and classical kinetic theory will be discussed.