| Adrian Adams | Director | 23 Jan 2001 | 8 Jun 2001 | British | 74 years |
| Andreas Rummelt | Director | 21 Oct 1999 | 1 Jan 2005 | British | 69 years |
| Anne Wirtz | Director | 25 Mar 2014 | 9 Feb 2017 | Belgian | 57 years |
| Benjamin James Michael Holgate | Secretary | 27 Sept 2010 | 31 Jan 2016 | British | - |
| Bryan George Kerr | Director | 14 Jun 1991 | 13 Mar 1997 | British | 82 years |
| Carlo Gargiulo | Director | 1 Oct 2020 | 13 Apr 2021 | Italian | 44 years |
| Chinmay Umesh Bhatt | Director | 1 Apr 2021 | 31 May 2022 | Dutch | 52 years |
| Colin Patrick Maher | Secretary | 18 Jun 2010 | 27 Sept 2010 | British | - |
| Cynthia Helena Chiaramitara | Director | 9 Feb 2017 | 22 Aug 2019 | Brazilian | 49 years |
| David Nicholas Henderson James | Director | 14 Jun 1991 | 31 Dec 1992 | British | 93 years |
| David Thomas Ashton | Director | 23 Jan 2001 | 27 Sept 2001 | British | 66 years |
| David William Hardy | Director | 1 Jul 1991 | 31 Jul 1996 | British | 95 years |
| Edgar Fullagar | Director | 21 Apr 1997 | 23 Apr 2002 | British | 86 years |
| Edgar Humberto Arrocha | Director | 26 Aug 2014 | 15 Aug 2016 | Usa | 55 years |
| Francois Leplattenier | Director | 14 Jun 1991 | 27 Jun 1997 | Swiss | 86 years |
| Gary Mark Connors | Director | 12 Oct 2011 | 25 Mar 2014 | British | 59 years |
| Gordon John Cummins | Director | 20 May 2004 | 1 Feb 2006 | South African | 55 years |
| Hans Kindler | Director | 13 Sept 1991 | 18 Jan 1999 | Swiss | 87 years |
| Hans Ruedi Durr | Director | 14 Jun 1991 | 14 Jun 1991 | Swiss | 95 years |
| Haseeb Ahmad | Director | 28 Mar 2017 | 1 Apr 2021 | British | 49 years |
| Helen Roberts | Secretary | 11 Mar 2008 | 18 Jun 2010 | British | - |
| Hugh Michael O'dowd | Director | 15 Oct 2015 | 16 Sept 2016 | American | 60 years |
| Ian Edmund Ferguson Stewart | Secretary | 14 Jun 1991 | 13 Mar 1997 | British | - |
| Ian Frederic Hay Davison | Director | 1 Jul 1991 | 31 Aug 1991 | British | 94 years |
| Ian Johnson | Director | 22 Aug 2019 | 15 Dec 2023 | British | 61 years |
| Ina Quinn | Director | 8 May 2019 | 1 Oct 2020 | Irish | 45 years |
| Jason Mark Brooks | Director | 9 May 2019 | 8 Apr 2025 | British,australian | 53 years |
| Jeremiah Carmel Collins | Director | 5 Sept 2007 | 12 Oct 2011 | Irish | 60 years |
| Jeremiah Carmel Collins | Director | 15 Aug 2016 | 9 May 2019 | Irish | 60 years |
| John Anthony Brewer | Director | 1 Sept 1992 | 31 Dec 1996 | British | 90 years |
| John Barry Clarkson | Director | 25 Jul 2001 | 5 Sept 2007 | British | 75 years |
| John Stewart Fraser | Director | 14 Jun 1991 | 31 Mar 1996 | Australian | 94 years |
| Juan Maria Andres Mascunana | Director | 16 Jan 2013 | 15 Aug 2016 | Spanish | 61 years |
| Keith Roy Saveal | Director | 18 Jan 1999 | 8 Jun 2001 | British | 77 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 Richard Edward Thirkettle | Director | 31 Jan 1997 | 18 Jan 1999 | British | 81 years |
| Paul Richard Edward Thirkettle | Secretary | 13 Mar 1997 | 23 Jan 2001 | British | - |
| Peter Krebser | Director | 18 Jan 1999 | 21 Oct 1999 | Swiss | 74 years |
| Ralph Saemann | Director | 14 Jun 1991 | 14 Jun 1991 | Swiss | 97 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 Metcalfe | Director | 31 Jan 1997 | 27 Nov 1997 | British | 88 years |
| Richard Samuel Cullen | Secretary | 1 Jan 2021 | 20 Jul 2022 | - | - |
| Sally Jane Jennings | Secretary | 23 Jan 2001 | 11 Mar 2008 | British | - |
| Sandipkumar Shantilal Kapadia | Director | 6 Mar 2012 | 26 Aug 2014 | American | 55 years |
| Stefan Hans Stroppel | Director | 19 Jan 1998 | 23 Jan 2001 | Swiss | 67 years |
| Subhanu Saxena | Director | 11 May 2005 | 26 Aug 2009 | British | 61 years |
| Susan Ann Webb | Director | 26 Aug 2009 | 1 Sept 2015 | British | 62 years |
| Terence Anthony Barnett | Director | 6 Apr 1996 | 13 Mar 1997 | British | 82 years |
| Teresa Jose | Director | 1 Jul 2009 | 6 Mar 2012 | Indian | 57 years |
| Thomas Jeffrey Van Laar | Director | 1 Jan 2005 | 16 Jan 2013 | American | 72 years |
| William Drummond Paris | Director | 14 Sept 2001 | 22 Apr 2005 | British | 74 years |