The following list of past fellows is approximately chronological. The first fellow, Guyan Robertson, began in October 1974.
The links are to MathSciNet (for which you will need a subscription).
Silouanos Brazitikos;
Brent Pym;
Charles Strickland-Constable;
Kevin Hughes;
Hendrik Suess;
Martin Lotz;
Teru Thomas;
Paul de Medeiros;
Gergely Berczi;
Stefan Kolb;
Nicolas Guay;
Simon Kristensen;
Tristam de Piro;
Konstantin Feldman;
Djoko Wirosoetisno;
H Dickinson;
Michael Batty;
David Calderbank;
Jonathan Woolf;
Vladimir Bavula;
Iain Gordon;
Nets Katz;
Alexei Kovalev;
John Hunton;
Alan H Forrest;
Martin Evans;
Antony Maciocia;
Vadim Kaimanovich;
Jason Rush;
T K Dutta;
Stephen Slebarski;
Jim Howie;
Haibao Duan;
Guyan Robertson.