Encyclopedias, Almanacs, Transcripts, and Maps
- Sisinnius I, Patriarch of Constantinople
- Sisinnius II, Patriarch of Constantinople
- Sisinnius, Pope
- Siskind, Aaron
- Sister Formation Movement
- Sisteron
- Sisters Adorers of the Precious Blood
- Sisters for Christian Community
- Sisters of Charity, Federation of
- Sisters of Christian Doctrine, Martyrs of, Bb.
- Sisters of Divine Providence
- Sisters of Divine Providence of Kentucky
- Sisters of Divine Providence of Texas
- Sisters of Mercy
- Sisters of Providence
- Sisters of Providence of St. Mary-of-the-Woods
- Sisters of the Adoration of the Blessed Sacrament
- Sisters of the Most Holy Sacrament
- Sisters, Faithful Companions of Jesus
- Sistine Chapel, Restoration of