

| Saguntum, Spain | Sacerdos of Saguntum |
| Sailors | Brendan, Erasmus (Elmo), Francis of Paola, Nicholas of Myra |
| Saint Ives, Cornwall | Ia |
| Saint Ives, England | Ivo |
| Saint Mellyan, Cornwall | Melaine of Rennes |
| Saint Teath, Cornwall | Teath |
| Saint Vitus's dance nervous disorder; rheumatic chorea | Vitus |
| Salamanca, Spain | John of Sahagun |
| San Gemini, Italy | Geminus |
| San Marino | Marinus |
| San Miguel de Allende, Mexico | Michael the Archangel |
| Santa Ana Indian Pueblo | Anne |
| Santa Clara Indian Pueblo | Clare of Assisi |
| Santa Fe, New Mexico, USA | Francis of Assisi |
| Santo Domingo, Dominican Republic | Our Lady of Ransom |
| Sardinia | Maurice |
| Sassano, Italy | John the Baptist |
| Savings banks | Anthony Claret |
| Savona, Italy | Our Lady of Mercy |
| Savoy | Maurice |
| Saxony | Willihad |
| Scandinavia | Ansgar |
| Scholars | Bridgid of Ireland, Thomas Aquinas |
| Scholars, scripture | Jerome |
| School teachers | John Baptist de la Salle |
| Schools | Thomas Aquinas |
| Schools of law | Raymond of Peņafort |
| Schools, Catholic | Thomas Aquinas |
| Schools, all Christian | Joseph Calasanctius |
| Scientists | Albert the Great |
| Scotland | Margaret, Andrew, Apostle |
| Scripture scholars | Jerome Emiliani |
| Sculptors | Claude, Luke, Four crowned martyrs, Louis |
| Sea, those associated with the | Francis of Paola |
| Security forces | Michael the Archangel |
| Security forces, Andorran | Our Lady Help of Christians |
| Security forces, French | Genevieve (Genofeva) |
| Security forces, Peruvian | Rose of Lima |
| Security guards | Matthew |
| Segovia, Spain | Venantius |
| Seminarians | Charles Borromeo |
| Senior citizens | Our Lady of Consolation, Teresa of Jesus Jornet e Ibars |
| Serbia | Sava |
| Serbian peoples | Sebastian |
| Sergio Osmena, Zamboanga del Norte, Philippines | Philip Benizi |
| Servants | Martha, Notbunga |
| Servants (women) | Zita |
| Seville, Spain | Ferdinand III of Castile |
| Shepherds | Our Lady of Lapurdo, Paschal Baylon |
| Shoemakers | Cyprian of Carthage, Homobonus |
| Shorthand writers | Cassian of Imola |
| Sibenik, Croatia | Michael the Archangel |
| Sicily | Andrew, Apostle, Vitus |
| Sick | John of God, Camillus de Lellis, Michael the Archangel |
| Sick, of Poland | Mary, The Health of the Sick |
| Siena Italy | Ambrose Sansedoni of Siena, Catherine of Siena |
| Signals, military | Gabriel the Archangel |
| Silesia | Hedwig |
| Silversmiths | Andronicus, Eligius (Eloi) |
| Sisak, Croatia | Quirinus |
| Sisters of Mercy | Elizabeth of Hungary |
| Sithney, Cornwall, England | Sithney |
| Skaters | Lidwina |
| Skiathos Island, Greece | Panagia Kastriani |
| Skiers | Bernard of Montjoux, Andronicus (with Athanasia), Our Lady of Graces |
| Skin diseases | Antony the Abbot |
| Skopelos Island, Greece | Riginos |
| Slander | John Nepomucene |
| Sleepwalkers | Dymphna |
| Slovakia | Our Lady of the Assumption |
| Slovenes | Virgilius |
| Snake bite victims | Hilary, Pirminus, Vitus |
| Social justice | Joseph, Martin de Porres |
| Social workers | Louise de Marillac, John Francis Regis |
| Soldiers | George, Martin of Tours, Maurice, Sebastian |
| Soldiers, American | Joan of Arc |
| Soldiers, French | Joan of Arc, Louis |
| Soldiers, Paraguayan | Mary, on feast of her Assumption |
| Solomon Islands | Michael the Archangel |
| Sonsbeck (Santbeck), Germany | Gerebernus |
| Sorrento, Italy | Antoninus of Sorrento |
| South Africa, Southern Africa | Our Lady of the Assumption |
| South America | Rose of Lima, Our Lady of Guadalupe |
| South Carolina, USA | Mary the Virgin Mother |
| South Dakota, USA | Our Lady of the Prairie |
| Spain | James the Greater, John of Avila, Our Lady of Ransom, Immaculate Conception of Mary |
| Spanish conquistadors | James the Greater |
| Spanish poets | John of the Cross |
| Spanish secular clergy | John of Avila |
| Spas | John the Baptist |
| Speakers (Orators) | John Chrysostom |
| Speleologists, Italian | Benedict, Abbot |
| Spelunkers, potholers | Benedict, Abbot |
| Spinners | Parasceva |
| Spiritual directors of clergy | Joseph Cafasso |
| Spiritual exercises | Ignatius of Loyola |
| Sportsmen and women, Belgian | Our Lady of Chevremont |
| Sri Lanka | Mary, Immaculate, Our Lady of Lanka |
| Sri Lanka (formerly Ceylon) | Lawrence, Our Lady of Madhu, Thomas, Apostle |
| St Vincent de Paul Societies | Vincent de Paul |
| St. Antony's Fire | Antony the Abbot |
| Stafford, England | Bettelin |
| Stamp collectors | Gabriel the Archangel |
| Stavenger, England | Swithun |
| Stenographers | Cassian of Imola |
| Stomach disorders | Timothy, Erasmus (Elmo) |
| Stone masons | Four crowned martyrs, Louis, Stephen |
| Storms, protection against | Vitus |
| Strasbourg, France | Arbogast |
| Strokes | Andrew Avellino |
| Students | Catherine of Alexandria, Thomas Aquinas, Gabriel Possenti |
| Students (examinees) | Joseph of Cupertino |
| Students in Jesuit colleges | Aloysius Gonzaga |
| Students, of Peru | Our Lady of Guadalupe |
| Students, women | Catherine of Alexandria |
| Sudan | Josephine Bakhita |
| Surgeons | Cosmas and Damian, Luke, Roch |
| Surveyors | Thomas, Apostle |
| Swabia, Germany | Meinrad |
| Sweden | Bridget, Eric of Sweden |
| Swimmers | Adjutor |
| Switzerland | Notbunga |
| Swordsmiths | Maurice |
| Syracuse, Sicily | Lucy of Syracuse |
| Syria | Barbara |
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