John Lothrop Motley was an American author and diplomat. As a popular historian, he is best known for his works on the Netherlands, the three volume work The Rise of the Dutch Republic and four volume History of the United Netherlands. As United States Minister to Austria in the service of the Abraham Lincoln administration, Motley helped to prevent European intervention on the side of the Confederates in the American Civil War. He later served as Minister to the United Kingdom during the Ulysses S. Grant administration.

John Maddison Morton was an English playwright who specialised in one-act farces. His most famous farce was Box and Cox (1847). He also wrote comic dramas, pantomimes and other theatrical pieces.

John Marshall was an American statesman, lawyer, and Founding Father who served as the fourth chief justice of the United States from 1801 until his death in 1835. He remains the longest-serving chief justice and fourth-longest serving justice in the history of the U.S. Supreme Court, and is widely regarded as one of the most influential justices ever to serve. Prior to joining the court, Marshall briefly served as both the U.S. secretary of state under President John Adams, and a representative, in the U.S. House of Representatives from Virginia, thereby making him one of the few Americans to serve on all three branches of the United States federal government.

John Marston was an English playwright, poet and satirist during the late Elizabethan and early Jacobean periods. His career as a writer lasted only a decade. His work is remembered for its energetic and often obscure style, its contributions to the development of a distinctively Jacobean style in poetry, and its idiosyncratic vocabulary.

John Edward Masefield was an English poet and writer, and Poet Laureate from 1930 until 1967. Among his best known works are the children's novels The Midnight Folk and The Box of Delights, and the poems The Everlasting Mercy and "Sea-Fever".

John Maynard Keynes, 1st Baron Keynes was an English economist and philosopher whose ideas fundamentally changed the theory and practice of macroeconomics and the economic policies of governments. Originally trained in mathematics, he built on and greatly refined earlier work on the causes of business cycles. One of the most influential economists of the 20th century, he produced writings that are the basis for the school of thought known as Keynesian economics, and its various offshoots. His ideas, reformulated as New Keynesianism, are fundamental to mainstream macroeconomics.

Lieutenant-Colonel John McCrae was a Canadian poet, physician, author, artist and soldier during World War I, and a surgeon during the Second Battle of Ypres, in Belgium. He is best known for writing the famous war memorial poem "In Flanders Fields". McCrae died of pneumonia near the end of the war. His famous poem is a threnody, a genre of lament.

John Merle Coulter, Ph. D. was an American botanist and educator. In his career in education administration, Coulter is notable for serving as the president of Indiana University and Lake Forest College and the head of the Department of Botany at the University of Chicago.

John Middleton Murry was an English writer. He was a prolific author, producing more than 60 books and thousands of essays and reviews on literature, social issues, politics, and religion during his lifetime. A prominent critic, Murry is best remembered for his association with Katherine Mansfield, whom he married in 1918 as her second husband, for his friendship with D. H. Lawrence and T. S. Eliot, and for his friendship with Frieda Lawrence. Following Mansfield's death, Murry edited her work.

John Miller Gray (1850-1894) was a Scottish art critic and the first curator of the Scottish National Portrait Gallery.