From the Nuttall encyclopedia (Project Gutenberg):
- Sidereal Year
- Sidlaw Hills
- Sidney Colvin
- Sigismund of Poland
- Silloth
- Silvestre Villeneuve
- Silvio Pellico
- Simon Bernard
- Simon Fraser Lovat
- Simon Patrick
- Simone Cantarini
- Simoom or Simoon
- Sindh Sind
- Sindia
- Siout or Asioot
- Sioux or Dakota Indians
- Sir Aldingar
- Sir Andrew Ague-Cheek
- Sir Andrew Freeport
- Sir Anthony Vandyck
- Sir Antony Cooke
- Sir Benjamin Brodie
- Sir Benjamin Ward Richardson
- Sir Charles Grandison
- Sir Creswell Creswell
- Sir David Ochterlony
- Sir de Lacy Evans
- Sir Edward Monson
- Sir Edward Pollock
- Sir Erasmus Wilson
- Sir F A Abel
- Sir Francis Bourgeois
- Sir Francis Wallace Grenfell
- Sir Frederick Bramwell
- Sir Frederick Cavendish Ponsonby
- Sir G B Airy
- Sir George Alexander Macfarren
- Sir George Cathcart
- Sir George Cornwall Lewis
- Sir George Cox
- Sir George Pollock
- Sir George Stewart White
- Sir Geraint
- Sir Giles Overreach
- Sir Guyon
- Sir Henry Blackwood
- Sir Henry Doulton
- Sir Henry Ellis
- Sir Henry Roscoe
- Sir Henry Rowley Bishop
- Sir Henry Saville
- Sir Henry W Moncreiff
- Sir Henry Wellwood Moncreiff
- Sir Howard Douglas
- Sir Hugh Willoughby
- Sir Isambard Brunel
- Sir James Archer Crowe
- Sir James Bremer
- Sir James Brisbane
- Sir John Birkenhead
- Sir John Bowling
- Sir John Cope
- Sir John Coventry
- Sir John Falstaff
- Sir John James Hugh Stewart-Murray Athole
- Sir John Taylor Coleridge
- Sir Jonathan Trelawney
- Sir Joseph Ayloffe
- Sir Joseph Edgar Boehm
- Sir Joshua Child
- Sir Philip Currie
- Sir Richard Bickerton
- Sir Robert Christison
- Sir Robert Grierson
- Sir Robert Harry Inglis
- Sir Robert Henry Sale
- Sir Roger de Coverley
- Sir Roger l'Estrange
- Sir Simonds d'Ewes
- Sir Stafford Henry
- Sir Sterndale Bennett
- Sir Thomas Craig
- Sir Thomas Hanmer
- Sir Tibert
- Sir Toby Belch
- Sir Travers Twiss
- Sir W Fergusson
- Sir Wemyss Reid
- Sir William Beechy
- Sir William Cubbit
- Sir William Forbes
- Sir William John Codrington
- Sirius or The Dog-Star
- Sirkar
- Sistova
- Siva or Civa
- Skager-Rack
- Skean-Dhu
- Skerryvore
- Slawkenbergius
- Sleswick-Holstein
- Sloejd
- Slough of Despond
- Smectymnuus
- Smelfungus
- Smithfield or Smoothfield
- Smoky City
- Snake-Stones
- Snorri Sturlason
- Sobraon
- Societe en Commandite
- Socinians
- Soeren Aaby Kierkegaard
- Sofronia
- Solar Myth
- Solar Year
- Soldan
- Solemn
- Solomon Alexander Hart
- Solomon Maimon
- Solomon of England
- Solomon of France
- Solomon's Ring
- Solway Moss
- Solyman II
- Sons of the Prophets
- Soochoo
- Sophie Charlotte
- Sophie Cottin
- Sorata
- Sordello
- Sorrows of the Virgin
- Sortes Virgilianae
- Sostratus
- Soudan or The Land of the Blacks
- South African Company