In this paper, we study a system of multiple positive solutions and stability results for nonlinear fractional delay differential equations involving p $$ p $$ -Laplacian operator. We derived adequate conditions to ensure that at least three nonnegative solutions exist by applying the conditions of the Leggett–Williams fixed-point theory and some Green function properties. Due to a small change in time-delay, we analyzed the Hyers–Ulam stability-type of the equation. We used Riemann–Liouville fractional differential definition, and we assumed that nonzero delay ϑ > 0 $$ \vartheta >0 $$ . In addition, for application purpose, comprehensive examples are given to ensure the effectiveness and feasibility of the results in this paper. Our proposed equation generalize some literature in the system.