Martha Gellhorn was an American novelist, travel writer and journalist, considered to be one of the greatest war correspondents of the 20th century. She reported on virtually every major world conflict that took place during her 60-year career. Gellhorn was also the third wife of American novelist Ernest Hemingway, from 1940 to 1945.

Gellhorn published numerous books, including a collection of articles on war, The Face of War (1959); a novel about McCarthyism, The Lowest Trees Have Tops (1967); an account of her travels (including one trip with Hemingway), Travels With Myself and Another (1978); and a collection of her peacetime journalism, The View From the Ground (1988).

Gellhorn published books of fiction, travel writing and reportage. Her selected letters were published posthumously in 2006.

On October 5, 2007, the United States Postal Service announced that it would honor five journalists of the 20th century times with first-class rate postage stamps, to be issued on Tuesday, April 22, 2008: Martha Gellhorn; John Hersey; George Polk; Ruben Salazar; and Eric Sevareid. Postmaster General Jack Potter announced the stamp series at the Associated Press Managing Editors Meeting in Washington. Martha covered the Spanish Civil War, World War II and the Vietnam War.

The Martha Gellhorn Prize for Journalism is named after her.