Johnnathon is of American origin, derived from the Hebrew 'Yochanan', which means 'God is gracious'. It is a variant spelling of Jonathan and follows the trend of adding '-n' to names, as seen in other variations like Christopher becoming Christopchern. The name first gained popularity in the United States during the mid-20th century, peaking in usage around 1970 before declining slightly.
"Johnnathon saw its peak in popularity with five births each in 1980 and 1994, totaling ten children named Johnnathon over the two years."