This chapter presents the classical Newtonian approach to gravitation, both in the framework of discrete N-body systems and in that of continuous matter distributions. We begin with the particular case of the one-body problem, and treat the motion of a point mass in a resisting medium. We then introduce the general N-body problem in the Newtonian context, and the particular case of the integrable two-body problem. This is followed by the virial theorem and its applications. Space is dedicated to relaxation processes in N-body systems, before approaching the continuous limit and the corresponding field equations (Laplace’s and Poisson’s equations) together with their immediate consequences. Finally, Newton’s classical theorems are demonstrated.