Sylvanus Thayer, American general and "father of West Point"
Sylvanus Bowser, American inventor
Sylvanus Morley (1883-1948), US anthropologist and Mayanist scholar
Sylvanus Urban, 18th century London writer and printer whose real name was Edward Cave
Sylvanus Bluff, character in "Hawbuck Grange" (1847) by R. S. Surtees
Sylvanus Heythorp, shipowner in "A Stoic" (1918) by John Galsworthy
Sylvanus Stone, eccentric old Professor of Natural Science writing crazy work called "Book of Brotherhood," living in his daughter (Mrs. Hilary Dalison)'s house, in "Fraternity" (1909) by John Galsworthy