Letts is a city in northern Louisa County, Iowa, United States, established in 1855.

[5] According to the United States Census Bureau, the city has a total area of 0.59 square miles (1.53 km2), all land.

There were 148 housing units at an average density of 261.2 per square mile (100.8/km2).

Hispanic or Latino persons of any race comprised 3.6% of the population.

There were 153 housing units at an average density of 259.3 per square mile (100.1/km2).

23.6% of all households were made up of individuals, and 11.5% had someone living alone who was 65 years of age or older.

There were 151 housing units at an average density of 272.1 per square mile (105.1/km2).

17.8% of all households were made up of individuals, and 7.5% had someone living alone who was 65 years of age or older.

[11] Some rural areas in proximity to Letts are zoned to the Muscatine Community School District.