- S, J.
- Saarinen, Eero
- Sadler II, William
- Salkeld, Cecil Ffrench
- Sargent, Louis
- Sarte, Maxime Real del
- Savage, Jim
- Savini, Augusto
- Sawyer, Richard
- Scanlon, James
- Scharf, William
- Schneider, Cristallerie
- Schonhauser, Franz H.
- School, Irish
- Schriever-Abeln, Fredrik
- Schubell, Madsen &
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- Schwatschke, John
- SCIOLARI, GAETANO
- Scott, Anthony
- Scott, James
- Scott, John
- Scott, Patrick
- Scott, William
- Scully, Harry
- Scully, Sean
- Secto
- Senior, William Shayer
- Set, A 1990 ECU
- Sets, Irish Stamp Year
- Settee, A Danish
- Sevilla, Ferran Garcia
- Sexton, Leonard
- Seymour, Dermot
- Shanahan, Sean
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- Sharkey, Sinead
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- Shaw, Dennis Orme
- Shaw, George Bernard
- Shaw, H G
- Shawcross, Neil
- Shayer, William Joseph
- Shelbourne, Anita
- Shepherd, Oliver
- Sheridan, Noel
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- Shiel, Sonia
- Shields, Mark
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- Sideboard, A
- SIGNORETTO, SILVANO
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- Skelton, John
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- SMITH, GEORGE
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- Smith, Richard
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- Smyth, Michael
- Smyth, Norman
- SOGNOT, LOUIS
- Solomon, Isaac
- Solomons, Estella
- Son, Frederick Mann &
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- Songs, Great Irish
- Soulages, Pierre
- Souter, Camille
- Souter, Michelle
- Souter-Robinson, Joan
- Spencer, William G.
- Spoons, A Set of 12 Feather Edge Dessert
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- Stand, An Umbrella
- Stangle, Hans
- Stanley, Jacqueline
- Staples, Robert Ponsonby
- Stapleton, Rose
- Starck, Philippe
- Staunton, Tracy
- Stephens, James
- Stevenson, Wendy
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- Stilnovo
- STILNOVO,
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- Stokes, Margaret
- Strahan, Robert
- Street, Evelyn
- Stuart, Imogen RHA, 1927-2024
- Style, Jorge Zalszupin
- Style, Willy Rizzo
- Sutherland, Graham
- Sutton, Ivan
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- Swift, Patrick
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- Synge, John Millington
- Szedleczky, Rudolf