Waldemar Birger Holberg was a Danish boxer. Born in Copenhagen, Denmark on May 29, 1883, he won the World Welterweight Championship on January 1, 1914, defeating Ray Bronson in Melbourne, Australia in a twenty round points decision. He was a fierce boxer with a KO percentage of 40% in the virtually complete boxing record displayed on BoxRec.

Ray Bronson briefly claimed the World Welterweight Boxing Title between February and December 1912.