The Adelegg is a forested, mountain range, up to 1,129 m above sea level (NN)[1] and 112 km2[2] in area, which is part of the northern foothills of the Alps, within the Westallgäu in the south German districts of Ravensburg and Oberallgäu.

They lie between the Untere Argen near Isny to the southwest and west, and Leutkirch to the northwest (both in the Baden-Württemberg district of Ravensburg), and between Altusried to the northeast, Wiggensbach to the east, Buchenberg to the southeast and the Wengener Argen near Weitnau to the south (all in the Bavarian district of Oberallgäu).

To the south it is adjoined by the mountain ridge of Sonneck on the far side of the Wengener Argen, which is not however part of the Adelegg landscape unit.

The highest mountain in the Adelegg range is the Schwarzer Grat, whose summit is located on Württemberg soil, just a few metres northwest of the Bavarian border, in the province of Tübingen.

The Wengener Argen flows past the Adelegg to the south in an east-west direction and empties into the Untere Argen that runs past the southwestern end of the mountains from southeast to northwest, before its waters flow into Lake Constance and thence into the Rhine.