| RefNo | Title | Date |
| IM/001452 | Flett, Sir John Smith | nd |
| NLB/27/8 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society] | 16 June 1903 |
| NLB/38/126 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society] | 17 June 1908 |
| RR/15/293 | Referee's report by John Wesley Judd, on a paper 'Report on the recent eruption of the Soufrière, St Vincent, and of a visit to Mount Pelée, Martinique' by Tempest Anderson and John Smith Flett | 12 November 1902 |
| RR/17/281 | Referee's report by Archibald Geikie, on a paper 'Photographical notes on the products of the eruptions of May 1902 at the Soufriere in St Vincent' by John Smith Flett | 6 February 1908 |
| NLB/25/300 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society] | 14 October 1902 |
| NLB/25/95 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society] | 8 August 1902 |
| NLB/25/276 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society], Geological Museum | 8 October 1902 |
| NLB/25/468 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society] | 8 November 1902 |
| NLB/25/580 | Copy letter from Robert William Frederick Harrison, to John Smith Flett, [Fellow of the Royal Society] | 21 November 1902 |
| NLB/25/445 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society], Geological Survey, Jermyn Street | 6 November 1902 |
| NLB/25/749 | Copy letter from Robert William Frederick Harrison, to Dr John Smith Flett, [Fellow of the Royal Society] | 18 December 1902 |
| NLB/26/175 | Copy letter from Robert William Frederick Harrison to, Dr John Smith Flett, Fellow of the Royal Society | 3 February 1903 |
| NLB/26/81 | Copy letter from Robert William Frederick Harrison to, Dr John Smith Flett, [Fellow of the Royal Society], Geological Survey, S.W. | 26 January 1903 |
| NLB/26/497 | Copy memo from Robert William Frederick Harrison to, Dr [John Smith] Flett, [Fellow of the Royal Society] | 31 March 1903 |
| NLB/26/590 | Copy letter from Robert William Frederick Harrison to, Dr [John Smith] Flett, [Fellow of the Royal Society] | 27 April 1903 |
| NLB/26/491 | Copy letter from Robert William Frederick Harrison to, Dr [John Smith] Flett, [Fellow of the Royal Society], Geological Survey | 31 March 1903 |
| NLB/37/194 | Copy letter from Archibald Geikie to Dr J [John] S [Smith] Flett | 13 February 1908 |
| NLB/37/66 | Copy letter from Robert William Frederick Harrison to Dr J S Flett | 17 January 1908 |
| NLB/37/893 | Copy Letter from Robert William Frederick Harrison to Dr J [John] S [Smith] Flett | 1 June 1908 |
| NLB/37/180 | Copy letter from Robert William Frederick Harrison to Dr A [Arthur] Smith Woodward FRS | 7 February 1908 |
| RR/17/280 | Referee's report by Alfred Harker, on a paper 'Photographical notes on the products of the eruptions of May 1902 at the Soufriere in St Vincent' by John Smith Flett | 3 February 1908 |
| NLB/53/270 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Dr. [John Smith] Flett, FRS | 23 June 1916 |
| EC/1913/07 | Flett, Sir John Smith: certificate of election to the Royal Society | |
| RR/41/55 | Referee's report by John Smith Flett, on a paper 'The relationship of climatic and geological factors to the composition of soil clay and the distribution of soil types' by Edward Mortimer Crowther | June 1930 |
| IM/001451 | Flett, Sir John Smith | 1922 |
| RR/20/117 | Referee's report by John Smith Flett, on a paper 'On a meteoric iron from winburg, orange free state' by W A Douglas Rudge | 10 December 1913 |
| NLB/68/939 | Copy letter from Henry Hallett Dale, Secretary of the Royal Society; to Sir John Flett, FRS | 4 December 1925 |
| NLB/67/733 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr [John Smith] Flett, FRS | 24 February 1925 |
| NLB/67/136 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr [John Smith] Flett, FRS | 1 November 1924 |
| NLB/71/307 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Sir John [Smith] Flett, FRS | 23 March 1928 |
| MC/18 | Volume 18 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1903 |
| RR/15/292 | Referee's report by Thomas George Bonney, on a paper 'Report on the recent eruption of the Soufrière, St Vincent, and of a visit to Mount Pelée, Martinique' by Tempest Anderson and John Smith Flett | November 1902 |
| NLB/37/272 | Copy letter from Robert William Frederick Harrison to Dr J [John] S [Smith] Flett, Geological Survey Office, 28 Jermyn Street, SW | 24 February 1908 |
| MC/18/93 | Letter from John [Smith] Flett, Geological Survey and Museum, 28 Jermyn Street, London, to [Walter] White | 23 January 1903 |
| MC/18/94 | Letter from John [Smith] Flett, Geological Survey and Museum, 28 Jermyn Street, London, to [Robert William Frederick] Harrison | 28 March 1903 |
| MC/18/95 | Letter from John [Smith] Flett, Geological Survey and Museum, 28 Jermyn Street, London, to [Robert William Frederick] Harrison | 1 April 1903 |
| NLB/43/249 | Copy letter from Robert William Frederick Harrison, to Dr [John Smith] Flett, [Fellow of the Royal Society] | 29 November 1910 |