Dag Hammarskjöld (1905–1961) served as the 2nd Secretary-General of the United Nations from 1953 to 1961.

Dag Hammarskjöld may also refer to:

Dag Hammarskjöld Foundation, a Swedish non-profit foundation Dag Hammarskjöld Library, a library at the headquarters of the United Nations Dag Hammarskjöld Medal, a posthumous award given by the United Nations Dag Hammarskjöld Plaza, a public park in Manhattan, New York Dag Hammarskjöld invert, an American postage stamp with a design error Dag Hammarskjöld Crash Site Memorial, a memorial in Copperbelt Province, Zambia Dag Hammarskjöld Stadium, a stadium in Ndola, Zambia Dag Hammarskjöld (constituency), a National Assembly constituency in Zambia Dag Hammarskjöld Middle School, a school in Wallingford, Connecticut

See also Dag (disambiguation) Hammarskjöld