Of Hebrew and/or Greek origin.
Janis is a variation of the name Jane which is an English form of the Old French name Jehanne, deriving from Johanna.
All of these feminine names are associated with the masculine name John, from the Greek name Ioannis.
Ioannis was borne by Hellenized Jews and is an adaptation of the Hebrew name Yochanan, meaning “graced by God”, therefore Janis also bears this meaning.
Other forms of the name, in English and other languages are Jane, Janice, Joan, Jean, Johanna, Jeanne, Joanna, Joni, Ivana, Gianna, Ioanna, Seana, Yanna, Giovanna, Hanna, Xoàna, Janette, Janelle, etc.
Janis reached #68 in Switzerland, in 2013.