New Kent County was established in 1654 from York County and was organized and settled by William Claiborne. The county's name originated because several prominent inhabitants, including William Claiborne, recently had been forced from their settlement at Kent Island, Maryland by Lord Baltimore upon the formation of Maryland. Claiborne had named the island for his birthplace in Kent, England. New Kent County is the birthplace of two U. S. Presidents' wives - Martha Washington and Letitia Christian Tyler. The church where George and Martha Washington are believed to have been wed, St. Peters, still holds services today. The Chickahominy Indians frequented this area as well as nearby Charles City County and two tribes are still well-established in this area.
Among the earliest settlers of New Kent County was Nicholas Gentry, who settled in New Kent in 1684. The parish register books of St. Peter's Parish show that Nicholas Gentry's daughter was baptized in the church in 1687. The records also reflect other Gentrys, probably Nicholas Gentry's relations, Peter and Samuel Gentry. As the result of arson confessed to by John Price Posey and Tho Green, and, allegedly, involving "a negro boy belonging to W. Chamberlayne" on 15 July 1787, many later county records were burned, making identifying relationships between family members difficult.
In November of 1719, a portion of New Kent County known then as St. Paul's Parish was formed into a separate county, now Hanover County.
In 2006, the U.S. Census Bureau rated New Kent County among the top 100 fastest growing counties in America.