Raymond William Jansen (born January 16, 1889 – March 19, 1934), was an American professional baseball player who played third base in the Major Leagues in 1910 for the St. Louis Browns.

Ray Jansen had a very short (one game) but unique career in Major League Baseball.

Although the 21-year-old local boy had never played a professional game in his life,[1] Jansen notched four singles in five at-bats.

The Browns lost the game to the Chicago White Sox, 9–1, and Jansen never played in the majors again.

This biographical article relating to an American baseball third baseman is a stub.