The thermoelastic problem of an orthotropic beam supported by an elastic foundation which resists lateral deformations as well as displacements parallel to the beam axis is considered. The solution for a relatively thick beam is obtained based on the first-order shear deformation theory. The problem is reduced to- the solution of an ordinary seventh-order differential equation which can be obtained in the closed form. The case of a slender beam is treated as a particular case of a more general solution for a shear deformable beam. © 1990 ASME.