The Wolseley 30/40 was a car of the upper middle class, introduced by Wolseley in 1914 as a smaller version of the 50.

They had a 6-cylinder engine with a 6864 cc capacity and water cooling. The car was built on a chassis with a length of 3,531 mm or 3,683 mm. The various bodies were between 4877 mm and 5029 mm long and 1803 mm wide.

In 1915 the production was stopped due to the war and resumed after 1919 (with an extended of 3759 mm). The bodies were 5,055 mm long and 1,778 mm wide.

The 30/40 was Wolseley's new flagship model after the First World War.

In 1921, the production was ceased.