From Britain or land of the Britons
A modern phonetic variant of Brittany, originally a geographic surname referring to people from the Brittany region of France. It became a popular given name in the late 20th century, though this specific spelling is quite rare.
Less common today
Britaney isn't in the latest US Top 1000. It last peaked at #5,512 in 1990.
US births per 5-year period, 1990βpresent (SSA data).