Lewis is a city in Cass County, Iowa, United States, along the East Nishnabotna River.

[3] According to the United States Census Bureau, the city has a total area of 0.50 square miles (1.29 km2), all land.

There were 188 housing units at an average density of 371.9 per square mile (143.6/km2).

Hispanic or Latino persons of any race comprised 3.9% of the population.

There were 200 housing units at an average density of 400.0 per square mile (154.4/km2).

28.4% of all households were made up of individuals, and 13.1% had someone living alone who was 65 years of age or older.

There were 196 housing units at an average density of 392.0 per square mile (151.4/km2).

31.1% of all households were made up of individuals, and 19.5% had someone living alone who was 65 years of age or older.