- Henrik Baarnhielm (QMUL)
- Comp. group theory
- 1st Apr 2007 to 16th May 2007
- Jens Bauch (Simon Fraser)
- Number theory
- 31st Jan 2018 to 1st May 2018
- David Bayer (Columbia)
- Algebraic Geometry
- 10th Dec 2000 to 15th Jan 2001
- Tobias Beck (Linz)
- Algebraic Geometry
- 4th Aug 2007 to 2nd Sep 2007
- Dan Bernstein (Eindhoven, Chicago)
- Cryptography
- 16th Jul 2004 to 14th Aug 2004
- 9th Dec 2019 to 13th Dec 2019
- Jean-François Biasse (University of Calgary)
- Number Theory
- 28th Jun 2010 to 2nd Jul 2010
- 14th Oct 2010 to 15th Mar 2011
- 8th Dec 2012 to 2nd Feb 2013
- Jérémy Le Borgne (Université de Rennes)
- Galois representations
- 28th May 2012 to 1st Jul 2012
- Wieb Bosma (Nijmegen)
- Comp. number theory
- 27th Mar 1997 to 23rd Apr 1997
- 25th Nov 1997 to 15th Dec 1997
- 22nd Jan 2002 to 15th Jul 2002
- 15th Jan 2006 to 31st Jan 2006
- 5th Jan 2012 to 19th Jan 2012
- John Bray (Birmingham)
- Group Theory
- 10th Mar 2004 to 2nd Apr 2004
- Richard Brent (ANU)
- Number Theory, Computer Science
- 2nd Dec 1997 to 4th Dec 1997
- 11th Feb 2007 to 14th Jun 2007
- 9th Feb 2009 to 13th Feb 2009
- Martin Bright (American University of Beirut)
- Arithmetic Geometry
- 23rd Jan 2003 to 21st Apr 2003
- 5th Dec 2010 to 15th Jan 2011
- 31st Dec 2012 to 29th Jan 2013
- Nicolas Brisebarre (ENS, Lyon)
- Number Theory
- 1st Sep 2008 to 1st Nov 2008
- Peter Brooksbank (Bucknell)
- Comp. group theory
- 24th Jan 2007 to 2nd Feb 2007
- 14th Jun 2007 to 2nd Jul 2007
- 12th Jun 2009 to 10th Jul 2009
- Gavin Brown (Loughborough)
- Algebraic Geometry
- 1st Oct 1998 to 1st Oct 1999
- 17th Aug 2000 to 16th Aug 2001
- 9th Aug 2003 to 31st Oct 2003
- 21st Nov 2004 to 31st Dec 2004
- 14th Jan 2009 to 11th Feb 2009
- 14th Dec 2009 to 20th Jan 2010
- 17th Dec 2010 to 17th Jan 2011
- 19th Dec 2011 to 17th Jan 2012
- Nils Bruin (Simon Fraser)
- Number Theory
- 20th Dec 2004 to 28th Feb 2005
- 3rd Jun 2009 to 10th Jul 2009
- 1st Nov 2010 to 15th Dec 2010
- Jarosław Buczyński (Texas A&M)
- Algebraic Geometry
- 1st Feb 2009 to 14th Feb 2009
- 22nd Apr 2010 to 8th May 2010
- Jack Button (Cambridge)
- Geometric Topology
- 6th Oct 2009 to 31st Oct 2009
