John Armstrong (1709-1779). —Poet, son of the minister of Castleton, Roxburghshire, studied medicine, which he practised in London. He is remembered as the friend of Thomson, Mallet, and other literary celebrities of the time, and as the author of a poem on The Art of Preserving Health, which appeared in 1744, and in which a somewhat unpromising subject for poetic treatment is gracefully and ingeniously handled. His other works, consisting of some poems and prose essays, and a drama, The Forced Marriage, are forgotten, with the exception of the four stanzas at the end of the first part of Thomson's Castle of Indolence, describing the diseases incident to sloth, which he contributed.

John Armstrong (1735– c. 1784) was an American soldier and land speculator from Surry County, North Carolina. During the American Revolutionary War he led units of the Surry County militia, advancing to the rank of Lt. Colonel.

John Ignatius Armstrong (July 10 1908 - March 10 1977) was an Australian political leader. He was a member of the Australian Labor Party in New South Wales and was elected to the national Senate for a term from 1937 to 1962.