This paper investigates a class of nonlinear p-Laplacian Hadamard fractional differential systems with coupled nonlocal Riemann-Stieltjes integral boundary conditions. First, we obtain the corresponding Green’s function for the considered boundary value problems and some of its properties. Then, by using the Guo-Krasnosel’skii fixed point theorem, some sufficient conditions for existence and nonexistence of positive solutions for the addressed systems are obtained under the different intervals of the parameters µ and ν. As applications, some examples are presented to show the effectiveness of the main results.