In this paper, we studied the Hyers–Ulam–Rassias stability for nonlinear Stratonovich Volterra integral equations. Also, we obtained stochastic operational matrix of modification of hat functions (MHFs) to numerically solve the nonlinear Stratonovich Volterra integral equations. Themain advantage of the proposed method is that it transforms problems under consideration into nonlinear systems of algebraic equations which can be simply solved. Finally, numerical examples are presented to certify convergence and accuracy of the method.