William Henry Smith, 5th Viscount Hambleden (born 18 November 1955) is a British peer, and descendant of the founders of the stationery group WH Smith.

Smith is the son of William Smith and Countess Maria Carmela Attolico di Adelfia. Through his paternal grandmother, he is a descendant of the Earls of Pembroke and the Vorontsov family.^[1] He succeeded to the title of Viscount Hambleden in 2012 upon the death of his father.

Smith married American Sara Suzanne Anlauf in 1983 and had two daughters, Sara Marie Celeste (b. 1986) and Alexandra Patricia (b. 1989). He was a film producer and restaurateur. He separated from his wife in 2003 and returned^{[clarification needed]} to Hambleden, Buckinghamshire, England.

He is in a relationship with singer Anni-Frid Lyngstad of ABBA with whom he lives in Switzerland.^[2]