Material models have been developed for characterizing the nonlinear stress-strain response of unidirectional glass and glass-ceramic matrix composites associated with progressive transverse matrix cracks perpendicular to fibers and ultimate composite failure. The models utilize a combined micromechanical and statistical approach. A simple micromechanical model has been used to evaluate the fiber and matrix stresses in the presence of transverse matrix cracks, fiber-matrix debonding, and residual stresses. Utilizing the chain-of-bundles approach, statistical models for matrix failure and fiber failure have been introduced to relate the density of transverse matrix cracks to the applied composite stress and to compute the final composite strength, respectively. Procedures to determine the required statistical and mechanical material parameters from experimental data have been established. The material models that are developed are applied to a glass matrix composite (C/borosilicate) and a glass-ceramic matrix composite (SiC/LAS).