Andreas was born into an ancient House of Khevenhüller, a German noble family originally from Franconia that had settled in Carinthia.

He was present at the Battle of Parma (29 June 1734), where Count Mercy, the Austrian commander, was killed, and after Mercy's death he held the chief command of the army in Italy until the arrival of Field Marshal Königsegg under whom he again distinguished himself at the Battle of Guastalla (19 September 1734).

In 1737 Khevenhüller was made Field Marshal, Prince Eugene recommending him to his sovereign as the best general in the service.

As commander-in-chief of the army on the Danube he not only drove out the French and Bavarian invaders of Austria in a few days of rapid marching and sharp engagements (January 1742), but overran southern Bavaria, captured Munich, and forced a large French corps in Linz to surrender.

They had two daughters: Khevenhüller wrote various instructional works for officers and soldiers: (Des G. F. M. Grafen von Khevenhüller Observationspunkte für sein Dragoner-Regiment (1734 and 1748) and a règlement for the infantry (1737)), and two important works on war in general, Kurzer Begriff aller militärischen Operationen (Vienna, 1756; French version, Maximes de guerre, Paris, 1771); and "Ideen vom Kriege," posthumously published in _Mittheilungen des k. und k. Kriegsarchiv_, Neue Folge 7--8 (1893—4): 286—441 and 319—97.