Turing, Alan

King's College Cambridge owns copyrights to some portraits, eg:

http://www.turingarchive.org/browse.php/K/7/9-16

but does not allow image files to be made available for download.

The National Portrait Gallery owns the rights to a 1951 portrait, but provides it under a CC-BY-NC-ND 3.0 license.

Credit as

• Alan Mathison Turing by Elliott & Fry, 29 March 1951, NPG x82217 © National Portrait Gallery, London / CC BY-NC-ND 3.0