A new numerical scheme via a Chebyshev series method is used to solve a family of linear fractional integro-differential equations, especially the Fredholm and Volterra equations. The linear fractional integro-differential equation can be transformed into a system of equations for the unknown function itself and its m derivatives by taking into account the mth order Chebyshev series of the unknown function at any point. Using MATLAB 2009 software, this approach provides a straightforward and closed-form solution to a linear fractional integro-differential equation. Finally, examples are provided to illustrate comparisons between the proposed Chebyshev series solution and some existing methods in this direction. The results obtained performed better in terms of quick convergence and stability over the existing Taylor series expansion methodologies.