From the experts:
Ann, the name of the sainted mother of the Virgin Mary, was among the top girls’ names for centuries, in both the original English Ann spelling and the French Anne. Both left the Top 100 around 1970 and show no signs of returning, with Anne is the middle of the US Top 1000 and Ann dropped out of sight. Once a go-to middle name, Ann has lost its stature in that position as well. Still, it's one of the most common names for girls of the 20th century.
Some more popular related names today include Hannah, Anna, and Annabelle.