This paper examines a class of hybrid iterative functional differential equations extended to the fractional domain. The model incorporates fractional dynamics through the \(\vartheta \) -Hilfer derivative, which generalizes classical fractional operators and provides a versatile framework for capturing complex memory effects. By reformulating the problem as an integral equation in the weighted function space \(\mathcal {D} = C_{2-z;\vartheta }([0, \mathcal {V}])\) , we establish existence and uniqueness results via Dhage’s fixed-point theorem combined with Banach’s contraction principle, and investigate Ulam–Hyers stability. The interplay of hybrid, iterative, and fractional structures enriches the mathematical framework and offers potential applications in biological and dynamical systems where feedback and memory mechanisms play a central role, while the use of the weighted space ensures well-posedness. The theoretical developments are illustrated through a representative numerical example, including both tabular and graphical representations.
