A new methodology for modeling tibio-femoral articular contact of a knee joint based on contact models of the classical contact mechanics is established. The given analytical models of articular contact are extended to the case of contact between low strain arbitrary linear elastic tissues, i.e., cartilages and meniscus. The approach uses the geometries of contact surfaces and the generalization of the Hertzian contact theory of non-conforming bodies with frictionless contact interaction between elastic articular tissues. The normal and tangential contact displacements are determined analytically based on the exact solutions for the spherical contact between the articular tissues of the knee. The non-linear stiffness (secant and tangential stiffness) of the knee joint’s elastic half-space is derived using the analytical relationships. The method is demonstrated by exploring a case study, and the results are compared with the current literature to verify the fidelity of the proposed analytical approach. The analytical models facilitate accurate contact mechanics of the knee joint. Researchers may now use these analytical models to develop knee surrogate models in multibody dynamics.