A solution technique is presented that calculates the static electric field at any point in a concentrated random dispersion of spherical particles when a uniform external electric field is applied across the dispersion. The particles may be of arbitrary size, position, and material composition. Using a rapidly converging iterative technique, the three electric field components may be calculated at any point in the medium or inside any particle. We assume all component materials are electrically isotropic and homogeneous and that the net charge on each particle is zero. This work is a first step in gaining a more fundamental understanding of electrostatic discharge phenomena through particulate‐filled systems. An important key is the use of the reduced dimension particle packing algorithms which simulate the microstructure of the particle pack.