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 and Jewish (Ashkenazic): metonymic occupational name for a baker of white bread rolls (see Semler). The German surname may also be a metonymic occupational name for a dealer in fine wheat flour.