Arthur Armstrong Denny (June 20, 1822 – January 9, 1899) was one of the founders of Seattle, Washington, and a leader of the pioneer Denny Party, a group of American pioneers credited with founding Seattle, Washington, because they settled at Alki Point on November 13, 1851.
Both his parents were of Irish decent. His father John Denny (1793–1875), fought in the War of 1812 and his Mother was an invalid who Arthur helped to care for after school.
He was Seattle's first postmaster and also donated land for the establishment of the University of Washington. Denny supported women's right to vote and introduced legislation in 1854 to allow white women of 18 years and older the right to vote but the resolution was voted down.
Denny, a devout christian and lifelong teetotaler, died at the age of 77 after a long illness.