The Sir John Simeon Correspondence comprises nearly 350 incoming letters.

Organized alphabetically, the collection begins with 9 incoming letters written between 1824 and 1846 to John's father, Sir Richard Simeon. Among this group are letters from political and religious figures, including an extensive missive from social reformer and abolitionist William Wilberforce concerning slavery in the West Indies.

The remainder of the letters span 1854 through 1870 and reflect Simeon's prominence in the social, political, and artistic circles on the Isle of Wight. For a time the only Roman Catholic Member of Parliament, Simeon, who was closely associated with the Oxford Movement, numbered among his correspondents many of the Victorian era's most influential politicians, statesmen (Frederick Temple Blackwood, Henry Bruce, Edward Cardwell, Hugh Childers, William Gladstone, George Goschen, George Lyttleton, William Monsell) and religious leaders (George Granville Bradley, Henry Manning, Arthur Stanley, William Ward, Samuel Wilberforce).

A classical scholar himself, Simeon's correspondents also included antiquarians (Frederic Madden, Thomas Wright), authors (Alexander Beresford-Hope, George Brodrick, Charles Kingsley, William Lecky, Anthony Sterling, Philip Henry Stanhope, William Stirling-Maxwell, George Venables), men of letters (James Froude, Theodore Martin, Richard Monckton Milnes), and scholars (Stephen de Vere, Benjamin Jowett, James Lacaita, Thomas May). With the arrival of Alfred Tennyson at Farringford, near Swainston, Simeon's circle of acquaintances broadened to include literary figures (William Allingham, Robert Browning, Pauline Craven, Aubrey de Vere, Georgiana Fullerton, Frederick Locker-Lampson, Charles Merivale, Caroline Norton, Laurence Oliphant, Coventry Patmore, Anthony Trollope).

Simeon's correspondents also included representatives of the visual and performing arts, including illustrators (Richard Doyle, Edward Lear), painters (William Boxall, Francis Grant, William Holman Hunt, Edwin Landseer, Frederic Leighton), photographers (Julia Margaret Cameron), sculptors (George Frederick Watts, Thomas Woolner), actresses (Helena Faucit Martin), and musicians (Charles Hamilton Aide, Charles Halle, Henry Russell).

While the Simeon letters are rich in associations with prominent Victorians, they are perhaps most valuable for their illumination of the intellectual, political, and social life which flourished on the Isle of Wight during that period.