From Old French Jo(h)anne, and so a doublet of Joan. This too was revived as a given name in its own right in the first half of the 20th century. It has to some extent been influenced by the independently formed combination Jo Anne.
German: Americanized spelling of Willeit, a variant of Willeitner, a habitational name from a more recent form of the place name Weillitnen in northern Bavaria. Willeit is probably also a topographic name from Middle High German wīl ‘small settlement’ + leite ‘slope’.