Westfield is a city in Plymouth County, Iowa, United States.

[2] It is the westernmost point in Iowa, this being due to a bend in the Big Sioux River.

[3] The nearby Broken Kettle wildlife refuge is one of the few places in Iowa where prairie rattlesnakes are commonly found.

Westfield is the purported home town of the central character, Jack Smurch, in James Thurber's 1931 short story "The Greatest Man in the World."

In the story, the fictional Smurch flies a second-hand, single-motored monoplane in July 1937 all the way around the world, without stopping.

[4] According to the United States Census Bureau, the city has a total area of 0.13 square miles (0.34 km2), all land.

29.6% of all households were made up of individuals, and 9.3% had someone living alone who was 65 years of age or older.

24.3% of all households were made up of individuals, and 9.5% had someone living alone who was 65 years of age or older.

About 3.8% of families and 3.6% of the population were below the poverty line, including 6.7% of those under the age of eighteen and none of those 65 or over.