Namesakes
Fictional Characters from Books:
1 character
Sydney Carton 1854 A Tale of Two Cities 
Fictional Characters from Television:
2 characters
Syd Hansen 1999 Providence
Sydney Bristow 2001 Alias
Hall-of-Famers:
1 ice hockey
(ice hockey) Syd Howe 1965
Nobel Prize Winners:
1 medicine
(medicine) Sydney Brenner 2002
Notable Actors and Entertainers:
4 actors
Sydney Greenstreet 1879-1954
Peter Lawford (middle name Sydney) 1923-1984
Sydney Chaplin 1926-2009
Sydney Sweeney 1997-
Notable Athletes:
1 ice hockey
(ice hockey) Syd Howe 1911-1976
Notable Filmmakers:
1 director
Sydney Pollack 1934-2008
Notable Scientists and Inventors:
1 biologist
Sydney Brenner 1927-2019
Notable Writers:
1 author
O. Henry (middle name Sydney) 1862-1910
Olympic Medalists:
3 gold, 1 silver/bronze
(silver/bronze) Sydney Battersby 1908; 1912 swimming - 1500 m freestyle; swimming - 4x200 m freestyle relay
(gold) Charles Sydney Smith 1908; 1912; 1920 water polo
(gold) Sydney Leroux 2012 football
(gold) Sydney McLaughlin-Levrone 2020 400 m hurdles; 4x400 m relay
Oscar Award Winners:
1 director
(director) Sydney Pollack 1986 Out of Africa
Saints:
1 blessed
Blessed Sidney Hodgson (a.k.a. Sydney) ?-1591