Under-secretary of state in the Shelburne administration.
Purser in the British navy (1775-80). Under-secretary of state (1782). Commissioner of the privy seal (1784). Under-secretary of war (1794). Secretary of the Admiralty (1795- 1804). Baronet (1802). Chief secretary for Ireland (1804). Lord commissioner of the Admiralty (1804-1806). Governor of Bombay (1812-19).
Son of Nicholas Nepean of Saltash, Cornwall. Married Margaret Skinner; five children.