Medieval Scottish diminutive of Jane, from Hebrew Yohanan meaning God is gracious.
Janet is a name with deep medieval roots, originating as a Scottish and Northern English diminutive of Jane, itself the feminine form of John. The chain of descent runs from the Hebrew Yohanan — meaning "God is gracious" — through the Latin Iohannes, the Old French Jehanne, and finally the affectionate diminutive suffix that Scottish speakers attached so readily. By the 15th century Janet was well established in Scotland as a name entirely independent of its origins, favored by ordinary families and noble ones alike.
Historical bearers lend the name a wide arc: Janet Douglas, Lady Glamis, was burned as a witch in 1537 on dubious charges, making her one of Scotland's most famous martyrs. In American culture Janet Leigh's scream in Hitchcock's Psycho (1960) and Janet Jackson's commanding pop career gave the name very different but equally indelible cultural fingerprints. The name also carried literary weight — Janet is the loyal, loving heroine of Charlotte Brontë's "Shirley," and appears throughout 19th-century fiction as the reliable, warm-hearted friend.
Janet peaked in English-speaking countries during the 1940s and 1950s, when it ranked among the top ten girls' names in the United States and United Kingdom. It has since retreated from the charts, giving it a certain mid-century vintage quality — the name of someone's capable, no-nonsense mother or aunt. That retro warmth has begun attracting a new generation of parents who see Janet not as dated but as genuinely classic: unfussy, friendly, and quietly due for rediscovery.