Pleasant Run is a census-designated place (CDP) in Colerain Township, Hamilton County, Ohio, United States.

[4] A Pleasant Run Post Office was established on March 4, 1846, and discontinued on February 15, 1907, with mail service being transferred to the post office in Mount Healthy.

[5] Pleasant Run was described in the 1940 American Guide Series as a rural village with 39 inhabitants.

[6] According to the United States Census Bureau, the CDP has a total area of 2.1 square miles (5.4 km2), all land.

Pleasant Run Farm is located to the east in neighboring Springfield Township.

26.8% of all households were made up of individuals, and 9.6% were someone living alone who was 65 years of age or older.

There were 1,791 housing units at an average density of 864.3 per square mile (333.7/km2).