Breanna is an anglicized form of the Irish Gaelic name Bríghid, which means "exalted one" or "the high one." The name can be traced back to the ancient Celtic goddess Brigid, who was associated with fire, poetry, and healing. In Irish mythology, Brigid was one of the most revered and widely-celebrated deities, and her name was later adopted as a popular given name for girls.

The name Bríghid is derived from the Old Celtic word "brig," meaning "high" or "exalted," and it was first recorded in the 5th century CE. The anglicized version, Breanna, emerged in the 20th century as a variant spelling, possibly influenced by the similar-sounding name Brianna.

One of the earliest recorded instances of the name Bríghid can be found in the 7th century hagiography of St. Brigid of Kildare, a Catholic saint who was likely inspired by the ancient goddess. St. Brigid is celebrated on February 1st, which was formerly the Celtic festival of Imbolc, associated with the goddess Brigid.

Throughout history, there have been several notable individuals named Breanna or variations of the name. One of the earliest recorded was Breanna of Rathangan (c. 1050-1120), an Irish noblewoman and patron of the arts. Another famous bearer of the name was Breanna Ní Dhubhchonna (c. 1340-1415), a renowned Irish poet and musician.

In more recent times, notable individuals named Breanna include Breanna Stewart (born 1994), an American professional basketball player and two-time Olympic gold medalist; Breanna Cameron (born 1984), an American model and actress; and Breanna Doyle (born 1995), an Irish professional footballer.

Overall, the name Breanna has a rich and ancient history, rooted in Celtic mythology and tradition, and has been borne by numerous notable individuals throughout the centuries.