This article presents new methodologies for investigating the optimal control outcomes of Hilfer fractional stochastic differential systems of order \(1<\psi <2\) with deviated arguments in Hilbert spaces. The main results are derived using tools from fractional calculus, stochastic analysis, Volterra integrodifferential equations, cosine families, and fixed point theory. We begin by employing Krasnoselskii’s fixed point theorem, the Laplace transform, and the Arzela-Ascoli theorem to establish existence results for Hilfer fractional stochastic Volterra integrodifferential systems with deviated arguments. Subsequently, we prove the existence of optimal pairs in these systems under certain sufficient conditions. Finally, a theoretical example is provided to illustrate the proposed results.
