Neighbouring towns and communities are, clockwise from the northwest, Willingen, Diemelsee, Twistetal, Waldeck, Vöhl, Lichtenfels (likewise all in Waldeck-Frankenberg) and Medebach (Hochsauerlandkreis in North Rhine-Westphalia).

The highest peaks in the Korbach municipal area are the Widdehagen (635 m) near Rhena (584 inhabitants) and the Eisenberg (562 m), which despite its name – meaning "Iron Mountain" – is well known for gold-bearing ore found there.

(each time at 31 December) On the hill upon which Saint Kilian's Church was later built, a Carolingian Imperial court already stood by 800.

The name Korbach (earlier "Corbach") comes from the Old High German Curbechi ("choosing place on the brook").

Curbechi had its first documentary mention in 980 when Otto II, Holy Roman Emperor yielded Korbach, Lelbach and Rhena to Corvey Abbey.

Also in other parts of the municipal area, clues can be found about settlement in early times, as for instance on the Wipperberg near Lengefeld.

Even nowadays, Korbach is still mostly Protestant, even though beginning in the 19th century, a great number of Catholics moved into the town.

On the other hand, the outlying communities to the west on the boundary with North Rhine-Westphalia are almost wholly (Hillershausen) or mostly (Nieder-Schleidern, Eppe) Catholic.

During the Seven Years' War the town was the site of the Battle of Korbach on 10 July 1760 between the French under the command of St. Germain and the Hanoverian, British and Hessian allies under Karl Wilhelm Ferdinand, the Hereditary Prince.

After the Second World War, the population rose sharply as those driven out of formerly German territories to the east flooded into town.

The town council's 31 seats are apportioned thus, in accordance with municipal elections held on 6 March 2016: Korbach's civic coat of arms might heraldically be described thus: Party per fess, above, in azure a bishop argent with shawl and mitre trimmed Or, in his hand dexter upraised a book Or, in his hand sinister a crozier Or dexter, below, in Or a halved eight-pointed star sable.

The eight-pointed star – only half of which appears in these arms – is quite a common charge in civic heraldry in Waldeck, the region in which Korbach lies, for the simple reason that it was the arms borne by the Counts of Schwalenberg-Waldeck, who were the town's rulers as the bishops' vassals beginning in 1227.

Also, the original 1236 seal shows him with the two objects transposed, holding the staff in his right hand, not the book.

There is no direct connection to the Autobahn network anywhere in the municipal area, the nearest interchanges being on the A 44 near Diemelstadt and Zierenberg, either way about 30 km away.

The stretch running to Kassel was reopened on 4 October 1998 (then one of the first examples in Germany of a railway line being reactivated).