This research develop the existence of solutions for a nonlinear third order ordinary differential equation with non-separated multi-point and nonlocal Riemann-Stieltjes boundary conditions. Standard tools of fixed point theorems are applied to prove the existence and uniquness results for the problem at hand. We used fixed point theorem due to Bohnenblust-Karlin to discussed the existence of solutions for the multi-valued case. We derive some examples to clarify our results.