Based on the concept of rhermoelasticity in a single‐phase elastic solid, we have investigated thermal stresses in a two‐phase composite media. A two‐phase composite slab and a concentric solid sphere were considered. The temperature distribution has been obtained by means of the Laplace transform. General formulas of thermal stresses in two‐phase composite are derived, and numerical examples are provided. For a constant average temperature and a constant surface temperature, the maximum transverse (or tangential) stress is located at the surface for both slab and sphere.