- Under Wellington's Command: A Tale of the Peninsular WarAuthor: G. A. (George Alfred) Henty, Walter PagetReleased on Project Gutenberg: December 29, 2006
- Under Western EyesAuthor: Joseph ConradReleased on Project Gutenberg: January 9, 2006
- Underground: Hacking, madness and obsession on the electronic frontierAuthor: Dreyfus, Suelette, Julian AssangeReleased on Project Gutenberg: November 1, 2003
- Understanding the ScripturesAuthor: Francis John McConnellReleased on Project Gutenberg: December 1, 2005
- Understood BetsyAuthor: Dorothy Canfield FisherReleased on Project Gutenberg: March 1, 2004
- UndertowAuthor: Kathleen Thompson NorrisReleased on Project Gutenberg: January 1, 2004
- UnderwoodsAuthor: Robert Louis StevensonReleased on Project Gutenberg: February 1, 1996
- UndineAuthor: La Motte-Fouqué, Friedrich Heinrich Karl, Freiherr de, Charlotte M. (Charlotte Mary) YongeReleased on Project Gutenberg: September 1, 2001
- UndineAuthor: La Motte-Fouqué, Friedrich Heinrich Karl, Freiherr de, Bunnett, F. E. (Fanny Elizabeth)Released on Project Gutenberg: February 1, 2003
- UndineAuthor: La Motte-Fouqué, Friedrich Heinrich Karl, Freiherr de, Macgregor, Mary [Adapter], Katharine CameronReleased on Project Gutenberg: July 4, 2006
- Une Vie, a Piece of String and Other StoriesAuthor: Guy de MaupassantReleased on Project Gutenberg: December 1, 2004
- Uneasy MoneyAuthor: P. G. (Pelham Grenville) WodehouseReleased on Project Gutenberg: October 1, 2004
- UngavaAuthor: R. M. (Robert Michael) BallantyneReleased on Project Gutenberg: June 6, 2007
- Ungava Bob: A Winter's TaleAuthor: Dillon Wallace, Palmer, Samuel M. [Illustrator]Released on Project Gutenberg: August 25, 2005
- Unhappy Far-Off ThingsAuthor: Lord DunsanyReleased on Project Gutenberg: October 21, 2004
- Union and DemocracyAuthor: Allen JohnsonReleased on Project Gutenberg: August 30, 2007
- UnitarianismAuthor: W. G. (William George) TarrantReleased on Project Gutenberg: February 1, 2004
- Unitarianism in America: A History of its Origin and DevelopmentAuthor: George Willis CookeReleased on Project Gutenberg: August 1, 2005
- United States Census Figures Back to 1630Author: United States. Bureau of the CensusReleased on Project Gutenberg: March 1, 1994
- United States Declaration of IndependenceAuthor: Thomas JeffersonReleased on Project Gutenberg: July 1, 1995
- United States Presidents' Inaugural Speeches: From Washington to George W. BushAuthor: United States. PresidentsReleased on Project Gutenberg: May 1, 1997
- Unity of GoodAuthor: Mary Baker EddyReleased on Project Gutenberg: August 25, 2005
- Unknown Mexico, Volume 1 (of 2): A Record of Five Years' Exploration Among the Tribes of the Western Sierra Madre; In the Tierra Caliente of Tepic and Jalisco; and Among the Tarascos of MichoacanAuthor: Carl LumholtzReleased on Project Gutenberg: August 4, 2005
- Unknown to History: A Story of the Captivity of Mary of ScotlandAuthor: Charlotte M. (Charlotte Mary) YongeReleased on Project Gutenberg: October 1, 2003
- Unleavened BreadAuthor: Robert GrantReleased on Project Gutenberg: January 10, 2005
- UnmannedAuthor: Stephen OliverReleased on Project Gutenberg: August 2, 2004
- UnspecialistAuthor: Yaco, Murray F., Kelly FreasReleased on Project Gutenberg: November 11, 2007
- Unspoken Sermons, Series I., II., and III.Author: George MacDonaldReleased on Project Gutenberg: October 1, 2005
- Untechnological EmploymentAuthor: Ed M. ClintonReleased on Project Gutenberg: October 22, 2007
- Unwise ChildAuthor: Randall GarrettReleased on Project Gutenberg: November 5, 2007
- Unwritten Literature of Hawaii: The Sacred Songs of the HulaAuthor: Nathaniel Bright EmersonReleased on Project Gutenberg: January 6, 2007
- Up from Slavery: An AutobiographyAuthor: Booker T. WashingtonReleased on Project Gutenberg: October 1, 2000
- Up in ArdmuirlandAuthor: Michael BarrettReleased on Project Gutenberg: January 4, 2006
- Up in the Clouds: Balloon VoyagesAuthor: R. M. (Robert Michael) BallantyneReleased on Project Gutenberg: June 6, 2007
- Up the ChimneyAuthor: Shepherd KnappReleased on Project Gutenberg: January 24, 2005
- Up the Hill and OverAuthor: Isabel Ecclestone MackayReleased on Project Gutenberg: December 1, 2003
- Up the River; or, Yachting on the MississippiAuthor: Oliver OpticReleased on Project Gutenberg: March 7, 2008
- Up To Date Business: Including Lessons in Banking, Exchange, Business Geography, Finance, Transportation and Commercial LawAuthor: Seymour EatonReleased on Project Gutenberg: February 6, 2007
- Up! Horsie!: An Original Fairy TaleAuthor: Clara de ChatelainReleased on Project Gutenberg: November 15, 2007
- Uppingham by the Sea: A Narrative of the Year at BorthAuthor: John Huntley SkrineReleased on Project Gutenberg: March 22, 2006
- Ups and Downs in the Life of a Distressed GentlemanAuthor: William L. (William Leete) StoneReleased on Project Gutenberg: December 24, 2007
- Urbain Grandier: Celebrated CrimesAuthor: Alexandre DumasReleased on Project Gutenberg: September 22, 2004
- Urban SketchesAuthor: Bret HarteReleased on Project Gutenberg: May 22, 2006
- UrsulaAuthor: Honoré de Balzac, Katharine Prescott WormeleyReleased on Project Gutenberg: October 20, 2005
- Us and the Bottle ManAuthor: Edith Ballinger PriceReleased on Project Gutenberg: June 1, 2004
- USAF Fact Sheet 95-03: Unidentified Flying Objects and Air Force Project Blue BookAuthor: United States. Air ForceReleased on Project Gutenberg: June 1, 2008
- UsuryAuthor: Calvin ElliottReleased on Project Gutenberg: May 27, 2007
- UtilitarianismAuthor: John Stuart MillReleased on Project Gutenberg: February 1, 2004
- UtopiaAuthor: More, Thomas, Saint, Henry MorleyReleased on Project Gutenberg: April 1, 2000
- Utopia of Usurers and Other EssaysAuthor: G. K. (Gilbert Keith) ChestertonReleased on Project Gutenberg: April 1, 2000
- V. V.'s EyesAuthor: Henry Sydnor Harrison, Raymond Moreau CrosbyReleased on Project Gutenberg: November 8, 2004
- Vagabondia: 1884Author: Frances Hodgson BurnettReleased on Project Gutenberg: June 8, 2008
- Vailima Letters: Being Correspondence Addressed by Robert Louis Stevenson to Sidney Colvin, November 1890-October 1894Author: Robert Louis StevensonReleased on Project Gutenberg: January 1, 1996
- Vain Fortune: A NovelAuthor: George Moore, Maurice GreiffenhagenReleased on Project Gutenberg: June 1, 2004
- Val d'Arno: Ten Lectures on the Tuscan Art Directly Antecedent to the Florentine Year of Victories; Given Before the University of Oxford in Michaelmas Term, 1873Author: John RuskinReleased on Project Gutenberg: July 1, 2005
- Valentine M'Clutchy, The Irish Agent: The Works of William Carleton, Volume TwoAuthor: William Carleton, Flanery, M. L. [Illustrator]Released on Project Gutenberg: June 7, 2005
- Valere aude (dare to be healthy)Author: Louis DechmannReleased on Project Gutenberg: February 8, 2005
- ValerieAuthor: Frederick Marryat, Wright-Nooth, W. [Engraver], Downing, D. [Illustrator]Released on Project Gutenberg: December 21, 2007
- Valerius Terminus: Of the Interpretation of NatureAuthor: Francis Bacon, Robert Leslie EllisReleased on Project Gutenberg: June 1, 2002
- Valley of DreamsAuthor: Stanley G. (Stanley Grauman) WeinbaumReleased on Project Gutenberg: August 11, 2007