- Sunshine FactoryAuthor: PansyReleased on Project Gutenberg: January 24, 2007
- Sunshine Sketches of a Little TownAuthor: Stephen LeacockReleased on Project Gutenberg: November 1, 2002
- Super Man and the Bug OutAuthor: Cory DoctorowReleased on Project Gutenberg: November 20, 2005
- SupermindAuthor: Randall Garrett, Laurence M. JaniferReleased on Project Gutenberg: August 16, 2007
- SupersededAuthor: May SinclairReleased on Project Gutenberg: September 24, 2004
- Superstition in all agesAuthor: Holbach, Paul Henri Thiry, baron d', Voltaire, Knoop, Anna, -, Jean MeslierReleased on Project Gutenberg: January 25, 2006
- Superstition unveiledAuthor: Charles SouthwellReleased on Project Gutenberg: April 24, 2005
- Supplement to Animal Sanctuaries in Labrador: Supplement to an Address Presented by Lt.-Colonel William Wood, F.R.S.C. Before the Second Annual Meeting of the Commission of Conservation in January, 1911Author: William WoodReleased on Project Gutenberg: February 21, 2005
- Supplemental Nights to the Book of the Thousand and One Nights — Volume 1 (of 6)Author: Burton, Richard Francis, SirReleased on Project Gutenberg: September 1, 2002
- Supplemental Nights to the Book of the Thousand and One Nights — Volume 2 (of 6)Author: Burton, Richard Francis, SirReleased on Project Gutenberg: September 1, 2002
- Supplemental Nights to the Book of the Thousand and One Nights — Volume 3 (of 6)Author: Burton, Richard Francis, SirReleased on Project Gutenberg: September 1, 2002
- Supplemental Nights to the Book of the Thousand and One Nights — Volume 4 (of 6)Author: Burton, Richard Francis, SirReleased on Project Gutenberg: September 1, 2002
- Supplemental Nights to the Book of the Thousand and One Nights — Volume 5 (of 6)Author: Burton, Richard Francis, SirReleased on Project Gutenberg: September 1, 2002
- Supplemental Nights to the Book of the Thousand and One Nights — Volume 6 (of 6)Author: Burton, Richard Francis, SirReleased on Project Gutenberg: September 1, 2002
- Supplementary Copyright Statutes, US Copy. OfficeAuthor: Library of Congress. Copyright OfficeReleased on Project Gutenberg: August 1, 2003
- Supply and DemandAuthor: Henderson, Hubert Douglas, Sir, John Maynard KeynesReleased on Project Gutenberg: January 1, 2004
- Supreme Personality: Fun in Living. A Doubt, Fear, and Worry CureAuthor: Delmer Eugene CroftReleased on Project Gutenberg: August 16, 2004
- Surfing the Internet: An Introduction: Version 2.0.2Author: Polly, Jean ArmourReleased on Project Gutenberg: January 1, 1993
- Surgical AnatomyAuthor: Maclise, JosephReleased on Project Gutenberg: January 28, 2008
- Surgical Experiences in South Africa, 1899-1900: Being Mainly a Clinical Study of the Nature and Effects of Injuries Produced by Bullets of Small CalibreAuthor: George Henry MakinsReleased on Project Gutenberg: May 3, 2007
- Surprising Stories about the Mouse and Her Sons, and the Funny Pigs.: With Laughable Colored EngravingsAuthor: UnknownReleased on Project Gutenberg: May 13, 2008
- Survival TacticsAuthor: Sevcik, Al, Irving H. NovickReleased on Project Gutenberg: March 30, 2008
- Susan: A Story for ChildrenAuthor: Amy WaltonReleased on Project Gutenberg: April 27, 2007
- Susan B. Anthony: Rebel, Crusader, HumanitarianAuthor: Lutz, AlmaReleased on Project Gutenberg: January 25, 2007
- Susan Clegg and a Man in the HouseAuthor: Anne Warner, Alice Barber StephensReleased on Project Gutenberg: October 3, 2007
- Susan Clegg and Her Friend Mrs. LathropAuthor: Anne WarnerReleased on Project Gutenberg: May 25, 2005
- Susan Clegg and Her Neighbors' AffairsAuthor: Anne WarnerReleased on Project Gutenberg: August 4, 2006
- Susan Lenox: Her Fall and RiseAuthor: David Graham PhillipsReleased on Project Gutenberg: March 1, 1996
- Sustained honor: The Age of Liberty EstablishedAuthor: John R. (John Roy) MusickReleased on Project Gutenberg: December 1, 2003
- Susy, a Story of the PlainsAuthor: Bret HarteReleased on Project Gutenberg: May 17, 2006
- Susâni: 1901Author: Louis BeckeReleased on Project Gutenberg: April 19, 2008
- Sutherland and Caithness in Saga-Time; or, The Jarls and The FreskynsAuthor: James GrayReleased on Project Gutenberg: May 18, 2005
- Suzanna stirs the fireAuthor: Emily Calvin Blake, Poole, Frederick V. [Illustrator]Released on Project Gutenberg: June 4, 2006
- Swallow: A Tale of the Great TrekAuthor: H. Rider (Henry Rider) HaggardReleased on Project Gutenberg: April 13, 2006
- Swan SongAuthor: Anton Pavlovich Chekhov, Marian FellReleased on Project Gutenberg: February 22, 2006
- Swann's WayAuthor: Marcel Proust, C. K. (Charles Kenneth) Scott-MoncrieffReleased on Project Gutenberg: December 1, 2004
- Sweet Cicely — or Josiah Allen as a PoliticianAuthor: Marietta HolleyReleased on Project Gutenberg: January 1, 2005
- Sweet Their Blood and StickyAuthor: Teichner, AlbertReleased on Project Gutenberg: May 22, 2007
- Sweetapple CoveAuthor: George Van SchaickReleased on Project Gutenberg: September 8, 2004
- Sweets for Leisure Hours: Amusing Tales for Little ReadersAuthor: Phillips, A., Phillips, E.Released on Project Gutenberg: November 12, 2007
- Swept Out to Sea; Or, Clint Webb Among the WhalersAuthor: W. Bert (Walter Bertram) FosterReleased on Project Gutenberg: December 2, 2007
- Swimming scientifically taughtAuthor: Frank Eugen Dalton, Dalton, Louis C. (Louis Cecil), -Released on Project Gutenberg: August 16, 2006
- Swirling WatersAuthor: Max RittenbergReleased on Project Gutenberg: July 8, 2006
- Swiss Family RobinsonAuthor: Johann David WyssReleased on Project Gutenberg: March 1, 2003
- Sword and crozier, drama in five actsAuthor: Indriði Einarsson, Lee M. (Lee Milton) HollanderReleased on Project Gutenberg: March 9, 2005
- Sword and Gown: A NovelAuthor: George A. (George Alfred) LawrenceReleased on Project Gutenberg: August 25, 2006
- Sword Blades and Poppy SeedAuthor: Amy LowellReleased on Project Gutenberg: August 1, 1997
- Sybil, Or, The Two NationsAuthor: Disraeli, Benjamin, Earl of BeaconsfieldReleased on Project Gutenberg: February 1, 2003
- Syd Belton: The Boy Who Would Not Go to SeaAuthor: George Manville Fenn, Gordon BrowneReleased on Project Gutenberg: May 8, 2007
- Sydney SmithAuthor: George William Erskine RussellReleased on Project Gutenberg: July 22, 2004
- Sylph Etherege: (From: "The Snow Image and Other Twice-Told Tales")Author: Nathaniel HawthorneReleased on Project Gutenberg: November 1, 2005
- Sylva; Or, A Discourse of Forest Trees. Vol. 1 (of 2)Author: John Evelyn, John NisbetReleased on Project Gutenberg: March 8, 2007
- Sylvia's Lovers — CompleteAuthor: Elizabeth Cleghorn GaskellReleased on Project Gutenberg: October 1, 2003
- Sylvia's Lovers — Volume 1Author: Elizabeth Cleghorn GaskellReleased on Project Gutenberg: October 1, 2003
- Sylvia's Lovers — Volume 2Author: Elizabeth Cleghorn GaskellReleased on Project Gutenberg: October 1, 2003
- Sylvia's Lovers — Volume 3Author: Elizabeth Cleghorn GaskellReleased on Project Gutenberg: October 1, 2003
- Sylvia's Marriage: A NovelAuthor: Upton SinclairReleased on Project Gutenberg: June 1, 2004
- Sylvie and BrunoAuthor: Lewis CarrollReleased on Project Gutenberg: August 1, 1996
- Symphonies and Their Meaning; Third Series, Modern SymphoniesAuthor: Philip H. (Philip Henry) GoeppReleased on Project Gutenberg: July 13, 2004
- Symphony No. 5 in C minor Opus 67Author: Ludwig van BeethovenReleased on Project Gutenberg: March 1, 1994