Although the Spessart is a roughly circular hill country, the main ridge extends from the southwest to the northeast. It is continued by the Odenwald in the southwest and by the Rhön in the northeast.
Its highest peak is the Geiersberg (586 m). Apart from the edges, the region is sparsely populated. Two nature parks called Bavarian Spessart and Hessian Spessart occupy large portions of the hills.