Untersteckholz was a municipality in the district of Aarwangen in the canton of Bern in Switzerland.

[1] Before the merge, Untersteckholz had an area, as of 2009[update], of 2.83 km2 (1.09 sq mi).

Of the rest of the land, 0.16 km2 (0.062 sq mi) or 5.7% is settled (buildings or roads).

17.7% of the total land area is heavily forested and 3.2% is covered with orchards or small clusters of trees.

Most of the population (as of 2000[update]) speaks German (97.6%), with Rhaeto-romance being second most common ( 0.6%) and Russian being third ( 0.6%).