From Brittany or Little Britain
A modern spelling variant of Brittany, referring to the region in northwest France. The name originally denoted people from the Celtic tribe of Britons who settled there. It gained massive popularity in the US during the 1980s and 1990s, though this specific spelling remains rare.
Less common today
Brittiny isn't in the latest US Top 1000. It last peaked at #2,133 in 1991.
US births per 5-year period, 1990βpresent (SSA data).