[2] Parnell, in Fillmore Township, Iowa County, Iowa, was named after Charles Stewart Parnell, a noble Irish statesman who had come to the American people to plead the cause of Ireland's land-impoverished peasants.

In 1884, the people of the little Irish town of Lytle City moved residences, stores, buildings, and families three miles west to where the railroad was beginning.

The people of Lytle City, who were mostly members of the Catholic Church, then became residents of Parnell.

In order to accommodate the pupils in town and in the western part of the district, school was held in a store building in Parnell in the winter of 1888–1889.

In 1889, a new one-room building was erected; and later in 1899, a four-room brick structure was built.

Early families of Parnell included the Shuells, Murphys, Hannons, Tiernans, Kellys, McDonalds, Dwyers, Callans, Eagletons, Lawlers, Tourneys, McCunes, Mullinex', Naughtons, Quinns, Sheridans, Mastersons, Ryans, Leahys, Murrins, Coakleys, Carneys, Sullivans and Weldons.

The St. Michael's Church, Cemetery, Rectory and Ancient Order of Hibernians Hall, located four miles to the east in the hamlet of Holbrook was listed on the U.S. National Register of Historic Places in 1983.

[4] According to the United States Census Bureau, the city has a total area of 0.17 square miles (0.44 km2), all land.

[5] As of the census of 2020,[7] there were 194 people, 81 households, and 48 families residing in the city.

The racial makeup of the city was 97.4% White, 2.1% Native American, and 0.5% from two or more races.

41.4% of all households were made up of individuals, and 11.5% had someone living alone who was 65 years of age or older.

34.1% of all households were made up of individuals, and 16.5% had someone living alone who was 65 years of age or older.

About 3.8% of families and 6.2% of the population were below the poverty line, including 7.8% of those under the age of eighteen and 2.9% of those 65 or over.