- The Slant BookAuthor: Peter NewellReleased on Project Gutenberg: December 8, 2005
- The Slave of the LampAuthor: Henry Seton MerrimanReleased on Project Gutenberg: October 1, 2005
- The Slave Trade, Domestic and Foreign: Why It Exists, and How It May Be ExtinguishedAuthor: Henry Charles CareyReleased on Project Gutenberg: April 1, 2005
- The Sleeper Awakes: A Revised Edition of When the Sleeper WakesAuthor: H. G. (Herbert George) WellsReleased on Project Gutenberg: April 1, 2004
- The Sleeping Bard; Or, Visions of the World, Death, and HellAuthor: Ellis Wynne, George BorrowReleased on Project Gutenberg: February 20, 2007
- The Sleeping BeautyAuthor: C. S. (Charles Seddon) Evans, Arthur RackhamReleased on Project Gutenberg: May 12, 2008
- The Sleeping Beauty Picture BookAuthor: Walter CraneReleased on Project Gutenberg: November 17, 2007
- The Sleeping-Car: A FarceAuthor: William Dean HowellsReleased on Project Gutenberg: February 1, 2001
- The Sleuth of St. James's SquareAuthor: Melville Davisson PostReleased on Project Gutenberg: October 1, 2001
- The Slim PrincessAuthor: George Ade, George F. KerrReleased on Project Gutenberg: February 1, 2004
- The SlowcoachAuthor: E. V. (Edward Verrall) LucasReleased on Project Gutenberg: February 1, 2000
- The Smalcald ArticlesAuthor: Martin Luther, F. (Friedrich) Bente, W. H. T. (William Herman Theodore) DauReleased on Project Gutenberg: June 1, 1995
- The Small House at AllingtonAuthor: Anthony TrollopeReleased on Project Gutenberg: October 1, 2003
- The Smiling Hill-Top, and other California sketchesAuthor: Julia M. (Julia Moss) Sloane, Carleton Monroe WinslowReleased on Project Gutenberg: March 2, 2006
- The Smoker's Year BookAuthor: Oliver Herford, Sewell CollinsReleased on Project Gutenberg: October 2, 2007
- The Smoky God; Or, A Voyage to the Inner WorldAuthor: Willis George EmersonReleased on Project Gutenberg: January 1, 2002
- The SnareAuthor: Rafael SabatiniReleased on Project Gutenberg: June 1, 2001
- The Snow-Drop: A Holiday GiftAuthor: Mower, Sarah S.Released on Project Gutenberg: March 1, 2004
- The snow-image, and other twice-told talesAuthor: Nathaniel HawthorneReleased on Project Gutenberg: May 1, 1996
- The Snowshoe TrailAuthor: Edison MarshallReleased on Project Gutenberg: February 26, 2008
- The Social Cancer: A Complete English Version of Noli Me TangereAuthor: José Rizal, Charles E. (Charles Edward) DerbyshireReleased on Project Gutenberg: October 1, 2004
- The Social Emergency: Studies in Sex Hygiene and MoralsAuthor: William Trufant Foster, Charles William EliotReleased on Project Gutenberg: May 18, 2005
- The Social History of SmokingAuthor: George Latimer AppersonReleased on Project Gutenberg: April 1, 2006
- The Soldier Boy; or, Tom Somers in the Army: A Story of the Great RebellionAuthor: Oliver OpticReleased on Project Gutenberg: January 4, 2005
- The Soldier of the ValleyAuthor: Nelson LloydReleased on Project Gutenberg: November 26, 2005
- The Solitary of Juan Fernandez, or the Real Robinson CrusoeAuthor: X.-B. (Xavier-Boniface) Saintine, Anne Topan Wilbur WoodReleased on Project Gutenberg: March 1, 2004
- The Solitary SummerAuthor: Elizabeth Von ArnimReleased on Project Gutenberg: June 1, 2004
- The Son of Clemenceau, A Novel of Modern Love and LifeAuthor: Alexandre DumasReleased on Project Gutenberg: October 1, 2004
- The Son of Monte-Cristo, Volume IAuthor: Jules LerminaReleased on Project Gutenberg: July 7, 2007
- The Son of Monte-Cristo, Volume IIAuthor: Jules LerminaReleased on Project Gutenberg: July 16, 2007
- The Son of My FriendAuthor: T. S. (Timothy Shay) ArthurReleased on Project Gutenberg: November 1, 2003
- The Son of TarzanAuthor: Edgar Rice BurroughsReleased on Project Gutenberg: November 1, 1993
- The Son of the WolfAuthor: Jack LondonReleased on Project Gutenberg: October 1, 2000
- The Song Book of Quong Lee of LimehouseAuthor: Thomas BurkeReleased on Project Gutenberg: April 1, 2000
- The Song Celestial; Or, Bhagavad-Gîtâ (from the Mahâbhârata): Being a discourse between Arjuna, Prince of India, and the Supreme Being under the form of KrishnaAuthor: Arnold, Edwin, SirReleased on Project Gutenberg: November 1, 2000
- The Song of HiawathaAuthor: Henry Wadsworth Longfellow, Morris, Woodrow W. [Editor]Released on Project Gutenberg: June 1, 2004
- The Song of our Syrian GuestAuthor: William Allen KnightReleased on Project Gutenberg: June 1, 2004
- The Song of RolandAuthor: C. K. (Charles Kenneth) Scott-MoncrieffReleased on Project Gutenberg: January 1, 1996
- The Song of Sixpence: Picture BookAuthor: Walter CraneReleased on Project Gutenberg: May 8, 2006
- The Song of the Blood-Red FlowerAuthor: Johannes LinnankoskiReleased on Project Gutenberg: July 18, 2004
- The Song of the CardinalAuthor: Gene Stratton-PorterReleased on Project Gutenberg: May 1, 1996
- The song of the exileAuthor: Wilfred S. (Wilfred Stradling) SkeatsReleased on Project Gutenberg: March 29, 2007
- The Song of the Flag: A National OdeAuthor: Eric MackayReleased on Project Gutenberg: May 12, 2008
- The Song of the LarkAuthor: Willa CatherReleased on Project Gutenberg: June 27, 2008
- The Song of the Stone WallAuthor: Helen KellerReleased on Project Gutenberg: April 1, 2004
- The Song of the Sword, and Other VersesAuthor: William Ernest HenleyReleased on Project Gutenberg: January 18, 2008
- The Songs of a Sentimental BlokeAuthor: C. J. (Clarence James) DennisReleased on Project Gutenberg: December 1, 2003
- The SonnetsAuthor: William ShakespeareReleased on Project Gutenberg: November 1, 1997
- The Sonnets of Michael Angelo Buonarroti and Tommaso Campanella; Now for the First Time Translated into Rhymed EnglishAuthor: Michelangelo Buonarroti, Tommaso Campanella, John Addington SymondsReleased on Project Gutenberg: November 1, 2003
- The sonnets, triumphs, and other poems of PetrarchAuthor: Francesco Petrarca, Thomas CampbellReleased on Project Gutenberg: January 31, 2006
- The Sorcery ClubAuthor: Elliott O'DonnellReleased on Project Gutenberg: December 10, 2004
- The Sorrows of a Show Girl: A Story of the Great "White Way"Author: McGaffey, KennethReleased on Project Gutenberg: December 1, 2003
- The Sorrows of Young WertherAuthor: Johann Wolfgang von Goethe, Boylan, R. Dillon (Richard Dillon)Released on Project Gutenberg: February 1, 2001
- The Sot-weed Factor: or, A Voyage to Maryland. A Satyr.: In which is Describ'd The Laws, Government, Courts and Constitutions of the Country, and also the Buildings, Feasts, Frolicks, Entertainments and Drunken Humours of the Inhabitants of that Part of America. In Burlesque Verse.Author: Cooke, EbenezerReleased on Project Gutenberg: May 7, 2007
- The soul of a bishopAuthor: H. G. (Herbert George) WellsReleased on Project Gutenberg: February 19, 2006
- The Soul of a ChildAuthor: Edwin BjörkmanReleased on Project Gutenberg: May 1, 2004
- The Soul of Democracy: The Philosophy of the World War in Relation to Human LibertyAuthor: Edward Howard GriggsReleased on Project Gutenberg: January 1, 2004
- The Soul of Man under SocialismAuthor: Oscar WildeReleased on Project Gutenberg: August 1, 1997
- The Soul of Nicholas Snyders; Or, The Miser of ZandamAuthor: Jerome K. (Jerome Klapka) JeromeReleased on Project Gutenberg: April 1, 1997
- The Soul of the Far EastAuthor: Percival LowellReleased on Project Gutenberg: August 1, 1998