| RefNo | Title | Date |
| MM/10/8 | Letter from Francisco de Borja Garcao Stockler to Thomas Young, Secretary, Royal Society | late 18th - early 19th century |
| MM/8/84 | 'Postscript to Dr Young's Letter on the Reduction of Experiments' | 1819 |
| DM/3/127 | Bill from William Cary, Mathematical Instrument Maker, for £28.4.0 | 31 May 1816 |
| DM/3/131 | Bill and Receipt, Thomas Young and Handley & Moore | November 1816-July 1817 |
| DM/4/125 | Letter from Thomas Young, Board of Longitude, to W T Brande, Secretary, Royal Society | 7 February 1824 |
| MS/242 | Letters to Thomas Young from Messrs Arago, Biot, Bessel, Berzelius, Fresnel, Malus, Humboldt, Laplace, Poisson and Wollaston | 17 December 1847 |
| IM/005040 | Young, Thomas | nd |
| CB/1/1/137 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden, Paris | 5 December 1814 |
| MM/14/3 | 'Estimate of Works proposed to be done for Dr Young at the Royal Institution Abermarle Street', by Joshua Ramsey | September 1827 |
| CB/1/1/136 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden, Paris | 25 November 1814 |
| CB/1/1/130 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden, Paris | 2 January 1814 |
| CB/1/1/141 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden | 14 February 1815 |
| IM/005038 | Young, Thomas | nd |
| MC/2/222 | Letter from Andrew Green, Prestbury near Cheltenham, to Dr. [Peter Mark] Roget, [Secretary of the Royal Society] | c. September 1836 |
| L&P/11/172 | Paper, 'On the theory of light and colours' [Bakerian Lecture] by Thomas Young | 1801 |
| L&P/12/60 | Paper, 'Experiments and observations relative to physical optica' [Bakerian Lecture] by Thomas Young | 1803 |
| L&P/10/51/1 | Paper, 'Observations on vision' by Thomas Young | 1793 |
| L&P/10/51 | Paper, 'Observations on vision' by Thomas Young | 1793 |
| L&P/10/51/2 | Plate, 'A vertical section of the ox's eye, of twice the natural size' by Thomas Young | 1793 |
| L&P/11/116/1 | Paper, 'Outlines of expriments and inquiries respecting sound and light' by Thomas Young | 1799 |
| L&P/11/144/2 | Plate, 'At the vertex of a given triangle, to place a given refracting surface, so that the incident and refracted rays may coincide with the sides of the triangle' by Thomas Young | 1800 |
| L&P/11/144/7 | Plate, 'Various forms of the image depicted by a cylindrical pencil of rays obliquely refracted by a spherical surface, when received on planes at distances progressively greater' by Thomas Young | 1800 |
| L&P/11/144/5 | Plate, 'The successive forms of the image of a large distant object, as it would be delineated by each refractive surface in the eye; to show how that form at last coincides with the retina' by Thomas Young | 1800 |
| L&P/12/86 | Paper, 'Essay on the cohesion of fluids' by Thomas Young | 1804 |
| L&P/12/32 | Paper, 'Account of some cases of the production of colours, not hithero described' by Thomas Young | 1802 |
| L&P/11/172/1 | Paper, 'On the theory of light and colours' [Bakerian Lecture] by Thomas Young | 1801 |
| L&P/11/144/1 | Paper, 'On the mechanism of the eye' by Thomas Young | 1800 |
| L&P/11/144/8 | Plate, 'The crenated zone, and the globules regularly arranged on the crystalline of the partridge' by Thomas Young | 1800 |
| L&P/11/144 | Paper, 'On the mechanism of the eye' by Thomas Young | 1800 |
| PT/8/21/3 | Plate, microscope arrangements by unknown artist | [1814] |
| CB/1/1/173 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden | 23 February 1820 |
| IM/005041 | Young, Thomas | 1996 |
| MM/9/7 | Letter from Benjamin Thompson, Count Rumford, Dover, to Sir Joseph Banks | 21 September 1801 |
| MM/8/83 | Letter from Dr Thomas Young, Admiralty, to Sir Joseph Banks | 20 May 1819 |
| DM/3/49B | Letter from J F W Herschel, Secretary, Royal Society, to JT Cooper | 19 November 1827 |
| CB/1/1/138 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden, Paris | 13 December 1814 |
| L&P/11/144/4 | Plate, 'The form of the ends of the optometer, when made of card. The apertures in the shoulders are for holding a lens: the square ends turn under, and are fastened together' by Thomas Young | 1800 |
| EC/1794/04 | Young, Thomas: certificate of election to the Royal Society | |
| CB/1/1/170 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden | 1 January 1820 |
| IM/005039 | Young, Thomas | nd |
| PT/1/15 | Letter, 'Extract of a letter from Dr [Heinrich] Olbers FRS to Dr [Thomas] Young, For Sec RS, announcing the discovery of a new planet' | 2 April 1807 |
| MC/1/62 | Letter from [Francisco de Borja Garcao] Stockler, Rio de Janeiro, to Thomas Young, Foreign Secretary of the Royal Society | 6 October 1819 |
| MC/1/84 | Letter from Thomas Young to [William] Hardy, chronometer maker, 5 Wood Street, Coldbath Square, London | 5 September 1822 |
| PT/9/10/2 | Plate, two figures of concentric rings and fringes by unknown artist | 6 October 1812 |
| PT/9/10/3 | Plate, four figures of concentric rings and fringes by unknown artist | 6 October 1812 |
| MC/1/129 | Letter from Richard Bingham, 4 Lamb's Conduit Place, to Thomas Young, Foreign Secretary of the Royal Society | 21 May 1825 |
| PT/8/21/2 | Plate, components of astronomical instruments by unknown artist | [1814] |
| PT/8/17/2 | Plate, diagrams showing joints and braces used in constructing a ship by unknown artist | [1814] |
| PT/9/10/4 | Plate, nine figures of concentric rings and fringes by unknown artist | 6 October 1812 |
| PT/8/17 | Paper, 'Remarks on the employment of oblique riders, and on other alterations in the construction of ships' by Thomas Young | [1814] |
| PT/9/10/1 | Manuscript, 'On some phenomena of colours, exhibited by thin plates' by John Knox | 6 October 1812 |
| PT/8/21/1 | Manuscript, 'An improved method of dividing astronomical circles and other instruments' by Capt Henry Kater | [1814] |
| PT/8/17/1 | Manuscript, 'Remarks on the employment of oblique riders, and on other alterations in the construction of ships' by Thomas Young | [1814] |
| PT/9/10 | Paper, 'On some phenomena of colours, exhibited by thin plates' by John Knox | 6 October 1812 |
| PT/9/10/6 | Plate, concentric rings and colour distribution by unknown artist | 6 October 1812 |
| PT/9/10/7 | Plate, three sets of concentric rings and colour distribution by unknown artist | 6 October 1812 |
| MC/1/155 | Letter from [George Biddell] Airy, Trinity College Cambridge, to Francis Baily, 37 Tavistock Place | 22 January 1828 |
| PT/9/10/5 | Plate, diagram of light reflecting off of lens by unknown artist | 6 October 1812 |
| MC/1/164 | Letter from Allen Francis Gardiner, 7 Tower Crescent, Clifton, to Dr. [Thomas] Young, Foreign Secretary of the Royal Society | 15 December 1828 |
| MC/1/163 | Letter from Allen Francis Gardiner, 7 Tower Crescent, Clifton, to Dr. [Thomas] Young, Foreign Secretary of the Royal Society | 10 December 1828 |
| PT/12/7/1 | Manuscript, 'Account of experiments made on the strength of materials' by George Rennie in a letter to Thomas Young | 3 June 1817 |
| PT/12/7/2 | Plate, plan and end of lever used in experiment by George Rennie | [1817] |
| PT/13/7 | Paper, 'On the anomaly in the variation of the magnetic needle as observed on ship-board' by Wm [William] Scoresby | 3 November 1818 |
| PT/17/9 | Paper, 'Experiments on the elasticity and strength of hard and soft steel' in a letter from Thomas Tredgold to Thomas Young | 16 December 1823 |
| PT/14/3 | Letter, explanation of accompanying paper from James Carson to Thomas Young | 25 September 1819 |
| PT/17/9/1 | Manuscript, 'Experiments on the elasticity and strength of hard and soft steel' in a letter from Thomas Tredgold to Thomas Young | 16 December 1823 |
| PT/17/9/2 | Plate, apparatus for measuring flexure by unknown artist | 16 December 1823 |
| PT/2/13 | Paper, 'Hydraulic investigations, subservient to an intended Croonian Lecture on the motion of the blood' by Thomas Young | [1808] |
| PT/3/1 | Paper, 'The Croonian Lecture on the functions of the heart and arteries' by Thomas Young | [1808] |
| AP/12/3 | Unpublished letter and extract, regarding thermometers from G [George] Cayley to [Thomas] Young | July-November 1825 |
| MC/2 | Volume 2 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1832-1838 |
| AP/11/25 | Unpublished paper, 'On the nature and properties of straight lined angles' by J [John] Walsh | 20 January 1824 |
| AP/12/3/1 | Unpublished letter, regarding thermometers from G [George] Cayley to [Thomas] Young | 15 November 1825 |
| AP/12/3/2 | Unpublished extract, 'Observations on Fahrenheit's and Reaumur's thermometers' by George Cayley | July 1825 |
| PT/8/21 | Paper, 'An improved method of dividing astronomical circles and other instruments' by Capt Henry Kater | [1814] |
| PT/14/5 | Paper, additional copy of 'On the elasticity of the lungs' by James Carson | 17 September 1819 |
| MC/1 | Volume 1 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1800-1831 |
| PT/12/7/3 | Plate, plan and end view of nippers used in experiment by George Rennie | [1817] |
| PT/14/4 | Paper, 'On the elasticity of the lungs' by James Carson | September 1819 |
| PT/15/25 | Paper, 'Calculation of some observations of the solar eclipse on the 7th of Sept [September] 1820' by Charles Rumker | [1821] |
| MC/5/52 | Letter from Tho [Thomas] Young, East Acton, to C [Charles Richard] Weld, [Assistant Secretary of the Royal Society] | 22 October 1852 |
| MC/5 | Volume 5 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1851-1858 |
| AP/9/23 | Unpublished paper, 'Observations on the new system of diagonal framing, introduced into HM [His Majesty's] Navy by R [Robert] Seppings Esq' by William Morgan | [1819] |
| AP/9/26 | Unpublished letter, 'On some general expressions for the limits of functions' from [Francisco de Borja Garção] Stockler to T [Thomas] Young | 25 February 1820 |
| PT/3/6 | Paper, 'A numerical table of elective attractions; with remarks on sequences of double decompositions' by Thomas Young | [1809] |
| AP/9/23/1 | Unpublished manuscript, 'Observations on the new system of diagonal framing, introduced into HM [His Majesty's] Navy by R [Robert] Seppings Esq' by William Morgan | [1819] |
| AP/9/23/2 | Unpublished diagrams, diagonal framing by [William Morgan?] | [1819] |
| AP/12/13 | Unpublished letters, regarding the quadrature of the circle from Charles Hudson to the President of the Royal Society [Davies Gilbert] | 1825-1828 |
| AP/12/13/4 | Unpublished copy letter, regarding algebraic solution to the quadrature of the circle from Charles Hudson to Thomas Young | 20 June 1826 |
| AP/12/12/5 | Unpublished diagram, triangles and semicircle inscribed in circle by Charles Hudson | 20 January 1825 |
| AP/12/12/3 | Unpublished diagram, triangle inscribed in circle attached to semicircle by Charles Hudson | 20 January 1825 |
| AP/12/12/6 | Unpublished diagram, triangle and overlapping circles by Charles Hudson | 20 January 1825 |
| AP/12/12/4 | Unpublished diagram, triangle inscribed in circle attached to semicircle by Charles Hudson | 20 January 1825 |
| AP/12/13/3 | Unpublished copy letter, regarding demonstration of the quadrature of the circle from Charles Hudson to Thomas Young | 9 June 1826 |
| AP/12/13/2 | Unpublished copy letter, regarding the quadrature of the circle from Charles Hudson to Thomas Young | 2 April 1825 |
| AP/12/11/2 | Unpublished drawings, accelerator for infantry by [Charles Hudson?] | 28 July 1825 |
| AP/12/11/1 | Unpublished letter, regarding an accelerator to facilitate the march of infantry from Charles Hudson to Thomas Young | 28 July 1825 |
| AP/12/12/2 | Unpublished diagram, segmented triangle by Charles Hudson | 20 January 1825 |
| AP/12/12/1 | Unpublished letter, regarding the quadrature of the circle from Charles Hudson to Thomas Young | 20 January 1825 |
| AP/12/14 | Unpublished letter, regarding leather storm sails and tents from Jacob Lawrence to T [Thomas] Young | 4 October 1826 |
| AP/13/12 | Unpublished paper, 'On the limits of the pulse in the arteries of the human body' by Lacon Wm [William] Lambe | [1828] |
| L&P/11/144/6 | Plate, 'Vertical section of my right eye, seen from without; twice the natural size' by Thomas Young | 1800 |
| PT/12/19 | Paper, 'Observations on the heights of mountains in the north of England' by Thomas Greatorex in a letter to Thomas Young | [1818] |
| PT/12/7 | Paper, 'Account of experiments made on the strength of materials' by George Rennie in a letter to Thomas Young | 3 June 1817 |
| P/0146 | Portrait of Young, Thomas | |
| PT/13/6 | Paper, 'Remarks on the advantage of multiplied observations in the physical sciences, and on the density and internal structure of the earth' by Thomas Young in a letter to Capt Henry Kater | 29 December 1818 |
| PT/17/10 | Paper, 'A short account of some observations made with chronometers in two expeditions sent out by the Admiralty at the recommendation of the Board of Longitude for ascertaining the longitude of Madeira and of Falmouth' in a letter from Dr J L [John Lewis] Tiarks to Thomas Young | [1824] |
| PP/10/14 | Paper, 'Problems in mechanism regarding trains of pulleys and drums of least weight for a given velocity ratio' by Henry Hennessy | 1887 |
| CB/1/1/144 | Letter from Sir Joseph Banks, Soho Square to Charles Blagden | 28 February 1815 |
| AP/1/3 | Unpublished paper, 'Estimate of the force of explosion of coal gas' by unknown author | [early 19th century] |
| AP/12/11 | Unpublished letter, regarding an accelerator to facilitate the march of infantry from Charles Hudson to Thomas Young | 28 July 1825 |
| AP/12/12 | Unpublished letter, regarding the quadrature of the circle from Charles Hudson to Thomas Young | 20 January 1825 |
| AP/13/28 | Unpublished paper, address as President of the Royal Society by Davies Gilbert | 30 November 1829 |
| L&P/11/116 | Paper, 'Outlines of expriments and inquiries respecting sound and light' by Thomas Young | 1799 |
| PT/73/12/7 | Diagram, mortality rates by [Thomas Young?] | [1826] |
| L&P/11/144/3 | Plate, 'At the vertex of a given triangle, to place a given refracting surface, so that the incident and refracted rays may coincide with the sides of the triangle' by Thomas Young | 1800 |