Susan Sontag (; January 16, 1933 – December 28, 2004) was an American writer, filmmaker, philosopher, teacher, and political activist. She mostly wrote essays, but also published novels; she published her first major work, the essay "Notes on 'Camp'", in 1964. Her best-known works include On Photography, Against Interpretation, Styles of Radical Will, The Way We Live Now, Illness as Metaphor, Regarding the Pain of Others, The Volcano Lover, and In America.
Sontag was active in writing and speaking about, or travelling to, areas of conflict, including during the Vietnam War and the Siege of Sarajevo. She wrote extensively about photography, culture and media, AIDS and illness, human rights, and communism and leftist ideology. Although her essays and speeches sometimes drew controversy, she has been described as "one of the most influential critics of her generation."