Johnatha is of American origin, derived from the Hebrew 'Yochanan', meaning 'God is gracious'. It gained popularity in the United States during the late 20th century and has since been used as both a first name and sometimes as a middle name.
"The name Johnatha had a consistent presence with five births each in the years 1973 and 1982, then a spike to eight in 1986 before significantly increasing to 34 births in 1989, bringing the total number of births over this period to 57."