Júlianna ("Júlia") Tudja (born 13 October 1979 in Vác, Pest) is a female hammer thrower from Hungary. Her personal best is 67.52 metres, achieved in April 2004 in Walnut, California.
Tudja was an All-American thrower for the USC Trojans track and field team, finishing runner-up in the hammer throw at the 2003 NCAA Division I Outdoor Track and Field Championships.