Meaning: A pet form of John, from the Hebrew Yochanan, 'God is gracious.' Used here for a girl though it is overwhelmingly a boy's name and nickname.Low
In 30 seconds: A friendly classic: Johnny is 'little John' — 'God is gracious' (said 'JAH-nee'). Much more often a boy's name — we note the lean.
Johnny is a diminutive of John, 'God is gracious,' from the Hebrew Yochanan. As a girl's name it is very rare; it is far more often a boy's name, which we note (said 'JAH-nee').
For girls it appears only rarely in the U.S., against heavy boys' use. Rare for girls, friendly, and classic.
Did you know? Johnny is a pet form of John, from the Hebrew for 'God is gracious' — a friendly, all-American nickname. It's used here for a girl, though it leans overwhelmingly to boys, which we note (said 'JAH-nee').
Overall data confidence 50%
References — Johnny — pet form of John; 'God is gracious'; strongly boy-leaning