Isadoro Anthony "Izzy" Jannazzo (January 31, 1915 Ensley, Alabama – June 18, 1995 Columbus, Ohio) was an American professional boxer who contended for the NYSE World Welterweight Championship against Barney Ross in November 1936, and took the Maryland version of the World Welterweight Championship in October 1940.
In 1937, he fought national welterweight champions before large crowds in Australia and Germany.
In 1940, he was listed as the world's top welterweight contender by some sources.