The eldest son of Sir William Wyndam Portal, 2nd Baronet, and Florence Elizabeth Mary Glyn, daughter of Hon.

Transferring back to the Life Guards (Special Reserve) in 1915, he was promoted lieutenant-colonel in 1916 when he took command of the Household Battalion.

He became General Cinema Finance Corporation's chairman, and worked very closely with J. Arthur Rank for many years.

In 1940, he became the chairman of the Coal Production Council, and he served in government as Additional Parliamentary Secretary to the Ministry of Supply from 1940 to 1942, and as Minister of Works and Planning from 1942 to 1944.

A GWR Castle Class locomotive, numbered 7000, was named Viscount Portal in his honour in 1946.