- Sackville, Maud Cecilia, Lady, 1
- Sackville-West, Vita (Lady Nicolson), 1, 2
- St Firmin, Chateau de, see Chantilly
- Salisbury, Arthur T. Gascoyne-Cecil, 3rd Marquess of, 1
- Salisbury, Cicely Alice, Marchioness of, 1, 2
- Salisbury, James E. H. Gascoyne-Cecil, 4th Marquess of, 1
- Salisbury, Robert A. J. Gascoyne-Cecil, 5th Marquess of (earlier Viscount Cranborne; ‘Bobbety’), 1, 2, 3
- Salvanoff, Dr, 1
- Salzburg, 1
- San Faustino, Princess, 1
- Sapieha, Prince and Princess, 1
- Sartre, Jean-Paul, 1
- Sassoon, Philip, 1, 2, 3, 4
- Schireson, Dr Henry, 1
- Searle, Alan, 1
- Sforza, Carlo, Count, 1
- Shannon, J. J., 1
- Shaw, Glen Byam, 1
- Shaw-Stewart, Patrick: relations with Diana, 1, 2, 3, 4, 5, 6‚ 7, 8, 9, 10, 11, 12, 13;
- death of mother, 1;
- killed in war, 1, 2;
- active service, 1, 2, 3, 4;
- on war deaths, 1;
- on Raymond Asquith’s love for Diana, 1;
- in parentage game, 1;
- and Diana in air raids, 1;
- bet with Duff, 1
- Sheean, Vincent, 1
- Sheffield, Lady, 1
- Sherwood, Hugh Michael Seeley, 1st Baron, 1
- Sherwood, Robert, 1
- Shriver, Eunice, 1
- Simon, Sir John, 1
- Simpson, Ernest, 1, 2
- Simpson, Mrs Wallis, see Windsor, Duchess of
- Sinclair, Archibald, 1, 2
- Singapore, 1, 2
- Singer, Isabelle, 1
- Sitwell, Sir Osbert, 1, 2, 3, 4
- Sitwell, Sir Sacheverell, 1
- Slessor, Sir John, 1
- Smuts, Jan Christian, 1
- Soraya, Queen, 1
- ‘Souls, The’, 1, 2
- Sphere (magazine), 1
- Stanislavsky, Konstantin S., 1
- Stanley, Blanche, 1
- Stanley, Maureen, 1
- Stanley, Oliver, 1
- Stanley, Venetia, see Montagu, Venetia
- Stanway (house), 1
- Steer, Philip Wilson, 1
- Stewart, James, 1
- Storrs, Sir Ronald, 1, 2, 3, 4
- Strachey, John, 1
- Strachey, Lytton, 1, 2
- Sturt, Lois, 1
- Sunday Evening Telegram, 1
- Sunday Times‚ 1
- Sutherland, Eileen, Duchess of, 1
- Sutton Courtenay (house), 1
- Sweden, 1
- Sweeny, Rifleman, 1