The T-matrix approach is applied to formulate electromagnetic scattering from an arbitrary number of spheres due to an incident plane wave. The representation of an incident plane wave in spherical vector wave functions from an arbitrary incident direction is given to facilitate subsequent derivation. The T-matrix formulation for an arbitrary number of spheres is obtained in two forms: an iterative form and a recursive form. It is shown that the recursive form is much more efficient than the iterative form when the number of spheres is greater than 2. The representations of the radar cross section, extinction and scattering cross sections in T-matrix form are provided. Numerical illustrations are given showing comparisons with calculations made by other investigators.