Howell was born in Newark, Delaware. He was a lawyer and soldier of the early United States Army. He served as captain and later major of the 2nd New Jersey Regiment from 1775 to 1779. Richard was a twin, his twin brother was Lewis Howell. Lewis was a physician for the 2nd New Jersey Regiment and died during the Revolutionary War. Richard was offered the role of judge advocate of the army, but turned down the appointment to practice law. He was clerk of the New Jersey Supreme Court from 1778 to June 3, 1793. He succeeded Thomas Henderson as Governor and served until 1801. Replaced as Governor by Joseph Bloomfield, Howell died the following year. He was the grandfather of Varina Howell, the second wife of Confederate President Jefferson Davis.
Howell Township in Monmouth County is named in his honour.