Bertha is a city in Todd County, Minnesota, United States.

[5] Bertha was platted in 1891, and named for Bertha Ristau, an early settler and wife of John Ristau who established the town's first Post Office in his log cabin store in 1880.

According to the United States Census Bureau, the city has a total area of 1.02 square miles (2.64 km2), all land.

The racial makeup of the city was 99.2% White, 0.2% African American, and 0.6% from two or more races.

40.0% of all households were made up of individuals, and 21.5% had someone living alone who was 65 years of age or older.

The racial makeup of the city was 98.72% White, 0.21% Native American, and 1.06% from two or more races.

33.6% of all households were made up of individuals, and 24.2% had someone living alone who was 65 years of age or older.