| Adrian Adams | Director | 23 Jan 2001 | 8 Jun 2001 | British | 74 years |
| Alexander Jetzer | Director | 1 Apr 1992 | 27 Sept 1995 | Swiss | 84 years |
| Alexandre Frederic Jetzer | Director | 1 Apr 1996 | 18 Apr 1997 | Swiss | 84 years |
| Benjamin James Michael Holgate | Secretary | 22 Jun 2011 | 31 Jan 2016 | - | - |
| Chinmay Umesh Bhatt | Director | 1 Apr 2021 | 31 May 2022 | Dutch | 52 years |
| Christopher David Snook | Director | 28 Jul 2008 | 6 Sept 2012 | British | 72 years |
| Christopher David Snook | Director | 19 Oct 2015 | 31 May 2017 | British | 72 years |
| David Rae Smith | Director | 1 Apr 1992 | 31 Dec 1992 | British | 106 years |
| David Thomas Ashton | Director | 23 Jan 2001 | 27 Sept 2001 | British | 66 years |
| Edgar Fullagar | Director | 7 Apr 1997 | 23 Apr 2002 | British | 86 years |
| Edgar Humberto Arrocha | Director | 26 Aug 2014 | 15 Aug 2016 | Usa | 55 years |
| Erwin Schillinger | Director | 26 Jun 2001 | 1 Mar 2007 | Swiss | 82 years |
| Felix Hermann Eichhorn | Director | 25 Jul 2018 | 8 Mar 2022 | Swiss | 64 years |
| Frederic Marcel Benoit Guerard | Director | 6 Sept 2012 | 31 Mar 2015 | French | 53 years |
| Gordon John Cummins | Director | 20 May 2004 | 1 Feb 2006 | South African | 55 years |
| Hans Kindler | Director | 13 Feb 1997 | 11 Dec 2000 | Swiss | 87 years |
| Harry Werner Kirsch | Director | 20 Jun 2013 | 10 Jul 2018 | Dutch | 60 years |
| Haseeb Ahmad | Director | 28 Mar 2017 | 1 Apr 2021 | British | 49 years |
| Helen Roberts | Secretary | 11 Mar 2008 | 22 Jun 2011 | British | - |
| Hugh Michael O'dowd | Director | 31 Mar 2015 | 16 Sept 2016 | American | 60 years |
| James Macindoe Romanes | Director | 1 Apr 1992 | 31 Jul 1994 | British | 98 years |
| Jason Mark Brooks | Director | 9 May 2019 | 8 Apr 2025 | British,australian | 53 years |
| Jonathan Richard Symonds | Director | 31 Mar 2010 | 20 Jun 2013 | British | 66 years |
| Juergen Mueller | Director | 1 Apr 1992 | 1 Oct 1994 | German | 85 years |
| Marie-andree Renee Gamache | Director | 29 Jun 2022 | 31 Oct 2024 | Canadian | 50 years |
| Michael John Fahey | Director | 4 Dec 2001 | 20 May 2004 | British | 60 years |
| Oriane Fanny Lacaze | Director | 15 Aug 2016 | 9 May 2019 | French | 46 years |
| Paul John Choffat | Director | 27 Sept 1995 | 1 Oct 1996 | Swiss | 76 years |
| Paul Richard Edward Thirkettle | Secretary | 1 Apr 1992 | 23 Jan 2001 | British | - |
| Paul Richard Edward Thirkettle | Director | 16 Jun 2000 | 1 Sept 2000 | British | 81 years |
| Peter Jager | Director | 1 Mar 2007 | 1 Jul 2008 | Dutch | 68 years |
| Raymond Breu | Director | 26 Aug 1993 | 18 Apr 1997 | Swiss | 80 years |
| Raymund Breu | Director | 11 Dec 2000 | 31 Mar 2010 | Swiss | 80 years |
| Rebecca Ann Weston | Secretary | 1 Feb 2016 | 1 Jan 2021 | - | - |
| Richard John Brazier | Director | 22 Feb 2006 | 1 Jul 2009 | British | 60 years |
| Richard Samuel Cullen | Secretary | 1 Jan 2021 | 20 Jul 2022 | - | - |
| Rolf Walter Schweizer | Director | 1 Apr 1992 | 1 Apr 1996 | Swiss | 95 years |
| Sally Jane Jennings | Secretary | 23 Jan 2001 | 11 Mar 2008 | British | - |
| Sandipkumar Shantilal Kapadia | Director | 3 Apr 2012 | 26 Aug 2014 | American | 55 years |
| Siegbert Erhard Wolfgang Ludtke | Director | 6 Jul 1998 | 31 May 2001 | Swiss | 86 years |
| Stefan Hans Stroppel | Director | 19 Jan 1998 | 23 Jan 2001 | Swiss | 67 years |
| Subhanu Saxena | Director | 22 Apr 2005 | 26 Aug 2009 | British | 61 years |
| Susan Ann Webb | Director | 26 Aug 2009 | 1 Sept 2015 | British | 62 years |
| Teresa Jose | Director | 1 Jul 2009 | 3 Apr 2012 | Indian | 57 years |
| Victor Alexander Bischoff | Director | 1 Apr 1992 | 26 Aug 1993 | Swiss | 79 years |
| William Drummond Paris | Director | 14 Sept 2001 | 22 Apr 2005 | British | 74 years |