William Nathaniel Massey (3 June 1809 – 25 October 1881) was a British barrister, author and Liberal Member of Parliament.

Massey studied law, being admitted as a student at the Inner Temple in November 1826, and was called to the bar in January 1844.

In August 1855 he was appointed Under-Secretary of State for the Home Department during the first ministry of Lord Palmerston, and became a member of Brooks's.

[1] Massey's major work was A History of England under George III, which was published in four volumes between 1855 and 1863, by J. W. Parker & Son.

In 1880, shortly before his last illness, Massey married Helen Henrietta, youngest daughter of the late Patrick Grant, Esq., Sheriff-Clerk of Inverness.