- Jacques Calmet (Karlsruhe)
- Computer Algebra
- 17th Jul 1997 to 19th Jul 1997
- Robin Candy (ANU)
- Graph theory
- 24th Jun 2019 to 28th Jun 2019
- Christian Caranica (LSU, Baton Rouge)
- Number Theory
- 12th May 2007 to 30th Jun 2007
- Jon Carlson (Georgia, Athens)
- Representation Theory
- 17th Apr 1994 to 22nd Apr 1994
- 8th Jan 1999 to 2nd Feb 1999
- 22nd Nov 1999 to 4th Dec 1999
- 15th Feb 2000 to 19th Feb 2000
- 7th May 2001 to 25th May 2001
- 6th Jul 2003 to 13th Jul 2003
- 13th Oct 2004 to 13th Nov 2004
- 15th May 2006 to 12th Jun 2006
- 8th Oct 2008 to 1st Nov 2008
- 6th Oct 2010 to 22nd Oct 2010
- 8th Apr 2012 to 21st Jun 2012
- 6th Oct 2013 to 25th Oct 2013
- 10th Nov 2015 to 28th Nov 2015
- 26th Oct 2017 to 27th Oct 2017
- Stefi Cavallar (CWI, Amsterdam)
- Comp. number theory
- 20th Oct 2000 to 6th Nov 2000
- Angela Chin (Malaya)
- Cohomology
- 1st Sep 2008 to 30th Sep 2008
- Serena Cicalo (Trento)
- 30th Apr 2007 to 23rd May 2007
- Arjeh Cohen (UT, Eindhoven)
- Lie Theory
- 5th Nov 2000 to 31st Dec 2000
- 19th Feb 2005 to 4th Mar 2005
- 1st Nov 2013 to 13th Nov 2013
- Brendan Creutz (Canterbury)
- Arithmetic Geometry
- 13th Nov 2017 to 17th Nov 2017
