Plymouth is a town in Box Elder County, Utah, United States.

According to the United States Census Bureau, the town has a total area of 0.5 square mile (1.4 km2), all land.

There were 114 housing units at an average density of 211.0 per square mile (81.5/km2).

The racial makeup of the town was 99.09% White, 0.30% Native American, and 0.61% from two or more races.

15.2% of all households were made up of individuals, and 7.6% had someone living alone who was 65 years of age or older.