The name Jo is a diminutive form of various longer names, primarily derived from the Hebrew name Joseph or the Latin name Josephus. Its origins can be traced back to ancient times, with roots in both biblical and classical traditions.

One of the earliest recorded instances of the name Jo appears in the Old Testament of the Bible, where it is used as a shortened form of the name Joseph, the son of Jacob and Rachel. Joseph's story is a significant part of the biblical narrative, depicting him as a dreamer and interpreter of dreams who rose to become a powerful figure in ancient Egypt.

In the classical world, the name Josephus was borne by the renowned Jewish historian Flavius Josephus, who lived from around 37 to 100 AD. His works, including "The Jewish War" and "Antiquities of the Jews," provide invaluable insights into the history and culture of ancient Judea and the Roman Empire.

Throughout the Middle Ages and Renaissance, the name Jo continued to be used as a diminutive form of Joseph or Josephus, particularly in European countries with Christian traditions. Notable figures from this period include Jo Bunō (1282-1348), a Japanese Zen Buddhist monk and poet, and Jo van Ammers-Küller (1521-1591), a Dutch feminist writer and humanist.

In more recent history, the name Jo has been embraced by individuals across various fields. Jo Rowling (born 1965), better known as J.K. Rowling, is the celebrated British author of the Harry Potter book series. Jo Cox (1974-2016) was a British politician and advocate for human rights, tragically murdered in 2016.

Other notable individuals with the name Jo include Jo Stafford (1917-2008), an American jazz singer and actress, and Jo Andres (1888-1945), an American filmmaker and artist known for his avant-garde experimental films.

While the name Jo has its roots in ancient Hebrew and Latin origins, it has transcended cultural boundaries and gained popularity across various regions and eras, embraced by individuals from diverse backgrounds and professions.