| SILVERSTONE (Paul H) | Stamp collector’s guide to Europe [1974] | N/A |
| SIMPSON (Thomas A) | The Postal History of Beverley [1986] | N/A |
| SIMPSON (Tracy W) | US postal markings 1851-61 & related mail services, with standards of condition & estimates of rarity [1959] | N/A |
| SINAIS (B) | Catalogue des obliterations navales francaises 1771-1986 [1987] | France, Maritime |
| SINAIS (B) | Catalogue des Obliterations Militaires Francaises 1900-1985 [1987] | France, Military |
| SINAIS (B) | Catalogue des Obliterations de Meetings d’Aviation et d’Agences Postales [1982] | Aviation |
| SINAIS (B) | Les Cachets d’Hopitaux en 1939-40 | Hospitals |
| SINAIS (Bernard) | Catalogue des obliterations des colonies francaises [1989] | Colonies, France |
| SINAIS (Bernard) | Catalogue des Cartes Postales de Franchise Militaire 1914 -1918 2 vols [1980-81] | Military |
| SINAIS (Bernard) | Catalogue des obliterations militaires francaises 1939-1945 [1979] | France, Military, WW2 |
| SINFIELD (LT CDR CA) | The Post in Portsmouth [1982] | N/A |
| SITAREK (J-M) | Catalogue des Obliterations de Meetings d’Aviation et d’Agences Postales [1982] | Aviation |
| SKAVARIL (Russell V) | St Helena Boer prisoners of war censor & camp handstamps [1991] | Military, POW |
| SKINNER (Hubert C) | United States cancellations 1845-1869: unusual and representative markings [1980] | N/A |
| SKIPTON (David M) | Postal censorship in Imperial Russia, 2 vols [1989] | Censorship, Russia |
| SLABBINCK (H) | Roue Ailee, Winged Wheel [2009] | Railways |
| SLADE (Edouard) | The pioneer days of aviation in Jersey, 2 vols [1965-66] | Aviation |
| SLATER (J) | A History of Portsoy Post Office [1999] | N/A |
| SLINGSBY (John) | The postal history of the Army of the Black Sea 1918-1923 [2004] | Military |
| SMIDTS (J), | Belgique 1879-1977: Les cachets a etoiles des depOts, depOts-relais, agences postales et haltes de | Belgium |
| SMITH (A D) | The development of rates of postage, an historical & analytical study [1917] | N/A |
| SMITH (Brian) | London’s postal history: section E; Inland Office cancellations 1844-1868, the horizontal diamonds [1992] | N/A |
| SMITH (Chester M) | Pennsylvania postal history. Lawrence (MA), Quarterman Publications Inc, 1976. viii, 564pp. [frontispiece] | N/A |
| SMITH (GW) | James Heath [1989] | N/A |
| SMITH (H) | The Austrian Post Offices in the Levant [2013] | N/A |
| SMITH (Hans) | Early mails between Constantinople and the West – from the beginnings to 1815: an outline. | N/A |
| SMITH (J C) | Civil censorship in Australia and dependencies 1939 to 1945 [1991] | Censorship, WW2 |
| SMITH (M) | Express Mail, After Packets and Late Fees in India before 1870 [2007] | N/A |
| SMITH (Max) | India post: index 1967-97 [1999] | N/A |
| SMITH (Michael) | An introduction to the postal history of Bristol [1997] | N/A |
| SMITH (Peter A Forrester) | Bishops Stortford – An Outline Postal History [1972] | N/A |
| SMITH (Peter A S) | Egypt. Stamps and Postal History [1999] | N/A |
| SMITH (Peter A S) | The travelling post offices of Egypt [1983] | Railways |
| SMITH (R C) | A supplement to Rhodesia A Postal History [nd] | N/A |
| SMITH (R C) | Rhodesia in Stamps (2nd supplement to Rhodesia, a Postal History) [1978] | N/A |
| SMITH (R C) | Rhodesia a postal history – its stamps, posts & telegraphs [1967] | N/A |
| SMITH (W J) | James Chalmers inventor of the adhesive postage stamp: a short summary of the invention [1970] | Rowland Hill |
| SMITH (William) | The history of the Post Office in British North America 1639-1870 [1920] | N/A |
| SMYTH (Eleanor C) | Sir Rowland Hill: the story of a great reform, told by his daughter [1907] | Rowland Hill |
| SMYTHIES (E A) | Canadian Roller Cancellations 1894 – 1930 [nd] | N/A |
| SMYTHIES (E A) | Canadian fancy cancellations of the nineteenth century 2nd ed, | N/A |
| SNELSON (J.K.) & GALLAND (R.B.) | The Returned Letter Offices of Great Britain to 1912 and Beyond [2017] | N/A |
| SNELSON (Ken) | UK Tax Marks for International Mail 1875 – 2000 [2007] | N/A |
| SNOWDEN (Neil) | The censor seals of the Anglo-Boer War 1899 to 1902 [1987] | Censorship, Military |
| SOER (John) | The Royal Mail in Leicestershire and Rutland [1997] | N/A |
| SOUTH AFRICA (UNION): POST OFFICE | Post Office Guide no 35, Sept 1947 | N/A |
| SOUTH AFRICA (UNION): POST OFFICE | Supplement to the Post Office Guide January 1945 | N/A |
| SOUTHERN RHODESIA | Post Office Guides 1926, 1948, 1951 | N/A |
| SPAFFORD (A O) | Monarchs of all they surveyed: the story of the Post Office surveyors | N/A |
| SPAULDING (Robert M) | Pacific crossings from Japan 1858-1879 | N/A |
