Pomonkey is named for the Pamunkey tribe of Native Americans that lived in the area. Dating from the early 19th century, the village of Bumpy Oak was renamed to Pomonkey when it was designated a postal stop. The former Pomonkey High School was one of two black segregated high schools in Charles County until the 1960s, and has a proud alumni association. From 1946 to 1970 the "Pomonkey Spoon Factory" manufactured wooden tools and small items.[not specific enough to verify] For several years, Maryland Airport has planned a 1,300 ft (400 m) expansion, including an energetics (explosives) technical center and business park employing over 3,000 people, but the plans are currently delayed by environmental concerns related to stormwater discharge into Mattawoman Creek.[not specific enough to verify] The Naval Research Laboratory has its Free Space Antenna Range on Bumpy Oak Road.
Pomonkey itself is a rural area, for which few statistics are available. Bryans Road, Maryland is the nearest community to Pomonkey for which data are available. However, the area lies at the meeting of ZIP codes 20616 (Bryans Road), 20640 (Indian Head) and 20646 (La Plata). As of 2000, Election District 7 (named for Pomonkey, but which includes Bryans Road and Indian Head) had a population of 11,859 persons. The racial breakdown was: 59.0% white, 35.8% black, 1.5% American Indian and Alaskan Native, 1.2% Asian, 0.1% Asian Indian, 0.2% Chinese, 0.6% Filipino, <0.1% Japanese, 0.1% Korean, <0.1% Vietnamese, 0.1% Other Asian, 0.1% Native Hawaiian and other Pacific Islander, 0.5% Other race, 1.8% two or more races.