In this paper, we study the stability of the Einstein static Universe against anisotropic homogeneous perturbations in energy–momentum squared gravity. For this purpose, we consider Bianchi IX space–time with isotopic matter distribution and use small perturbations on the fluid variables as well as scale factors. We consider particular models of this theory to explore stable modes of the Einstein cosmos for both conserved as well as nonconserved energy–momentum tensor. It is found that stable modes of the Einstein Universe appear in both cases for specific values of the equation of state parameter. The stable solutions increase for positive values of the model parameter. It is worth mentioning here that stable regions exist in contrast to general relativity. We conclude that stable solutions increase here compared to other alternative gravitational theories.