This paper introduces a fractional version of reaction‐diffusion equations with non‐local boundary conditions via a non‐singular fractional derivative defined by Atangana and Baleanu. The orthonormal discrete Legendre polynomials are introduced as suitable family of basis functions to find the solution of these equations. An operational matrix is derived for fractional derivative of these polynomials. A collocation method based on the expressed polynomials and their operational matrices is developed for solving such problems. The established method transforms solving the original problem under consideration into solving a system of algebraic equations. Some numerical examples are used to investigate the validity of the presented method.