Hartley is a city in O'Brien County, Iowa, United States.

[2] Hartley got its start around 1880, following construction of the Chicago, Milwaukee & St. Paul Railway through that territory.

[5] According to the United States Census Bureau, the city has a total area of 1.30 square miles (3.37 km2), all land.

There were 754 housing units at an average density of 566.9 per square mile (218.9/km2).

Hispanic or Latino persons of any race comprised 8.5% of the population.

There were 789 housing units at an average density of 607 per square mile (239/km2).

There were 803 housing units at an average density of 629.3 per square mile (243.0/km2).

Of all households, 32.6% were made up of individuals, and 18.9% had someone living alone who was 65 years of age or older.

Hartley celebrates Summerfest every year during the first weekend in August.

[11] The city also has two local parks: Neebel, which has a newly built public swimming pool and Shinkle.