Judy is a diminutive of Judith. Judith originates in Hebrew language and means "Judea woman". It is a feminine form of Judah. Judith was a character in the Book of Genesis. She is also the heroine of the Book of Judith, a part of the Old Testament. As a feminine given name it was most popular in the middle of the 20th century. Since then its usage has declined. Judy was popularized by the American actress and singer Judy Garland.