Ohmstal is a former municipality in the district of Willisau in the canton of Lucerne in Switzerland.

Of the rest of the land, 4.9% is settled (buildings or roads) and the remainder (0.7%) is non-productive rivers.

Of the settled areas, 2.23% is covered with buildings, 0.22% is industrial, 0.22% is classed as special developments, 0.22% is parks or greenbelts and 2.01% is transportation infrastructure.

The former municipality is located on the left sided of the Luthern river valley.

Most of the population (as of 2000[update]) speaks German (98.7%), with Portuguese being second most common ( 0.9%) and French being third ( 0.3%).

The age distribution, as of 2008[update], in Ohmstal is; 77 people or 24.2% of the population is 0–19 years old.

In the 2000 census[update] the religious membership of Ohmstal was; 249 (78.5%) were Roman Catholic, and 46 (14.5%) were Protestant.