From Old French Joanne, from Latin Joanna, from Koine Greek Ἰωάννα (Iōánna), from Hebrew יוֹחָנָה (Yôḥānāh, literally “God is gracious”), the feminized form of יְהוֹחָנָן (Yəhōḥānān) which produced John and its many doublets.
Doublet of Ivana, Jana, Jane, Janice, Janis, Jean, Jeanne, Jen, Joan, Joanna, Johanna, Juana, Shavonne, Sian, Siobhan, Shane, Shaun, Shauna, and Sheena.