Yarmouth is an unincorporated community and census-designated place in northwestern Des Moines County, Iowa, United States.

[3] In 1881, around the time the Burlington and Northwestern Railway arrived, the La Vega post office, originally about a mile to the east, was moved here and renamed Yarmouth.

[8] Yarmouth is located on a broad low ridge that has been identified as a terminal moraine of the Illinoian glaciation.

Geological investigation of wells drilled in Yarmouth led to the discovery of a paleosol on top of the pre-illinoian surface and buried under the terminal moraine.

[9] 205th Avenue passes north–south through Yarmouth at an elevation of 810 feet above sea level; this forms part of Des Moines County Highway X31.