Albert Freeman Africanus King (18 January 1841 – 13 December 1914) was an English-born American physician who was pressed into service at the assassination of Abraham Lincoln on 14 April 1865.

On 18 January 1841, King was born in Ambrosden, a village near Bicester in the Cherwell District of north-eastern Oxfordshire in England.

In November he became an Acting Assistant Surgeon to Major J. W. L. Daniel of 15th AL Infantry, Confederate States Army, and the University of Pennsylvania.

In 1864 he was appointed Acting Assistant Surgeon in the U.S. Army, and worked at the Lincoln Hospital, Washington, D.C.

During the American Civil War, King was in Washington, D.C. On 14 April 1865 he was in the audience at Ford's Theatre when President Abraham Lincoln was shot by John Wilkes Booth.

It was not until 1898 that Ronald Ross proved mosquitoes were a vector for malaria (he won the Nobel Prize for the discovery just four years later).

King died in Washington, D.C. due to senile debility, and is interred at Rock Creek Cemetery.