Abstract The Least squares approach is a robust and simple method for function approximation. Collocated Discrete Least Squares (CDLS) is a meshless method based on least squares technique enjoying symmetric and positive-definite properties. In this paper, the CDLS method is extended for the stream function-vorticity formulation of 2D incompressible Navier–Stokes equations. Shape functions are constructed using Radial Point Interpolation Method (RPIM) because of its robustness and simplicity. The accuracy of the proposed scheme is investigated through solving lid-driven cavity flow and backward facing step problems for the different Reynolds numbers.