In this work, a non-classical sinc-collocation method is used to find numerical solution of third-order boundary value problems. The novelty of this approach is based on using the weight functions in the traditional sincexpansion. The properties of sinc-collocation are used to reduce the boundary value problems to a nonlinear system of algebraic equations which can be solved numerically. In addition, the convergence of the proposed method is discussed by preparing the theorems which show exponential convergence and guarantee its applicability. Several examples are solved and the numerical results show the efficiency and applicability of the method.