S. Kellogg Stryker (February 5, 1902 – July 20, 1989), of New York City, was a stamp dealer recognized in the philatelic community as an expert on 19th century and 20th century postage stamps.
Stryker is noted for a number of rare philatelic “finds” of United States stamps, such as discovering the first unused copy of the 1923 one-cent Franklin (Scott 594), and the 1923 one-cent Franklin (Scott 596), both recovered from printer's waste.
Stryker also discovered a USIR watermark on the dollar value of the 1938 Presidential series of definitives (Scott 832B); he continued to search for more, and eventually found approximately four hundred more copies.
The Philatelic Foundation awarded Stryker the Mortimer Neinken Medal in 1989.
Stryker was named to the American Philatelic Society Hall of Fame in 1990.