Frederika is a city in Bremer County, Iowa, United States.

[4] According to the United States Census Bureau, the city has a total area of 0.20 square miles (0.52 km2), all land.

There were 113 housing units at an average density of 308.1 per square mile (119.0/km2).

There were 118 housing units at an average density of 590.0 per square mile (227.8/km2).

The racial makeup of the city was 98.4% White, 0.5% Native American, and 1.1% Asian.

39.6% of all households were made up of individuals, and 15.7% had someone living alone who was 65 years of age or older.

There were 122 housing units at an average density of 609.1 per square mile (235.2/km2).

36.5% of all households were made up of individuals, and 25.0% had someone living alone who was 65 years of age or older.

About 10.3% of families and 12.6% of the population were below the poverty line, including 25.8% of those under the age of eighteen and 6.1% of those 65 or over.