| Thomas Johnston | 1929 | |
| Archibald Noel Skelton | 1931 | 22 November 1935 |
| Joseph C Westwood | March 1931 | August 1931 |
| Joseph C Westwood | May 1940 | May 1945 |
| James Henderson Stewart | February 1952 | January 1957 |
| Niall Malcolm Stewart Macpherson | June 1955 | October 1960 |
| Edward Macmillan Taylor | June 1970 | July 1971 |
| Edward Macmillan Taylor | January 1974 | March 1974 |
| Rt Hon James Hamish Hector Northey Gray, Baron Gray of Contin | 1983 | 1986 |
| Samuel Laird Galbraith | May 1997 | |
| Calum Alasdair MacDonald | May 1997 | 28 July 1999 |
| Malcolm George Richardson Chisholm | 5 May 1997 | |
| Rt Hon Angus John Macdonald | 1998 | 1999 |
| Anne Catherine McGuire | 2002 | |
| Ian James Duncan, Baron Duncan of Springbank | 15 June 2017 | 26 July 2019 |
| Robin Caspar Walker | 26 July 2019 | 16 December 2019 |
| Douglas Gordon Ross | 17 December 2019 | 26 May 2020 |
| Malcolm Ian Offord, Baron Offord of Garvel | 30 September 2021 | |
| David James Duguid | 20 September 2022 | |
| John Robert Lamont | 27 October 2022 | |
| Donald Andrew John Cameron, Baron Cameron of Lochiel | 9 February 2024 |