The name Fiona is of Celtic origin, deriving from the Gaelic word "fionn" which means "fair" or "white". It has been a popular name in Ireland, Scotland, and parts of England for centuries.

The earliest known recorded use of the name Fiona dates back to the 8th century AD, when it appeared in ancient Irish manuscripts and historical records. Some scholars believe the name may have been inspired by the Irish legend of the female warrior Fionn, who was said to have fought alongside the mythical hero Finn MacCool.

In the Middle Ages, the name Fiona gained popularity among noble families in Scotland and Ireland. One of the earliest notable figures with this name was Saint Fiona of Kildare, an Irish abbess who lived in the 6th century AD and is venerated in the Catholic Church.

During the Renaissance period, the name Fiona was used by several prominent literary figures. In the 16th century, Scottish poet Robert Sempill wrote a ballad titled "The Life and Death of the Pious Robert Sempill of Beltrees, and his Wife Fiona Sempill". This work helped to further popularize the name in Scotland.

In the 19th century, Fiona became a more widely used name across the English-speaking world. One of the earliest notable examples is Fiona Macleod, the literary pseudonym used by Scottish writer William Sharp (1855-1905). Sharp wrote numerous works of poetry and prose under this name, helping to further establish Fiona as a recognizable and respected name.

Other notable historical figures named Fiona include:

1. Fiona Campbell-Walter (1932-2008), a British actress and author.
2. Fiona Stanley (born 1946), an Australian epidemiologist and public health researcher.
3. Fiona Avery (born 1966), a Canadian author and publisher.
4. Fiona Sheehan (born 1981), an Irish football player and coach.
5. Fiona Murtagh (born 1972), an Irish statistician and computer scientist.

The name Fiona has maintained its popularity in many parts of the world, particularly in Ireland, Scotland, and other Celtic regions, where it is often seen as a symbol of cultural heritage and tradition.