Julianna is the feminine of Julian — itself from Julius, the Roman family name. The root meaning is likely "youthful" or "downy-bearded" (an epithet of Jupiter). Saint Juliana of Nicomedia (early 4th century) was an early Christian martyr.
Julianna has been climbing steadily in the U.S. since the 1990s. The actress Julianna Margulies (ER, The Good Wife) is a prominent bearer. Today the name sits in the U.S. top 200.
Julianna reduces to nine — the number of youthful warmth.