In this book, an analytical solution developed for thermal elastic-plastic stress analysis of laminated composite plates is presented. This analytical solution is performed for satisfying thermal elastic- plastic stress-strain relations and boundary conditions for small plastic deformations. In this analysis, firstly, elastic-perfectly plastic (ideal plastic), secondly, linear hardening material properties are assumed, and the Tsai-Hill theory is used as a yield criterion. This thermal elastic- plastic stress analysis is carried out on a symmetric cross-ply [0o/90o]2 and symmetric angle- ply [30o/-30o]2 , [45o/-45o]2 , [60o/-60o]2 simply supported thermoplastic laminated plates subjected to thermal loads varying constantly and linearly through the thickness. Residual stresses are also obtained for all staking sequences.