Multiscale models play a key role in capturing the inelastic response of woven carbon fiber reinforced ceramic matrix composites. Due to the mismatch in the thermal properties between the constituents of plain weave carbon fiber/silicon carbide composites, microcracks are present in the as-produced composite. Capturing the initial damage state of the composite requires the development of a multiscale thermoelastic constitutive damage model. The developed model is used to simulate the elastic and damage behavior of a plain weave C/SiC composite system under thermal and mechanical loads. It is shown to accurately predict the composite behavior and serves as a valuable tool in investigating the physics of damage initiation and progression and the evolution in effective composite elastic moduli as a result of temperature changes and damage.