The name could be of a few different sources, it could be a Dutch and Limburgish short form of Sibilla. In Scandinavia, it is often viewed as either a short form of Ilsebill, Berit or even just a feminine form of Billy.
As of 2010, Billa was the 8th most popular female name in the Faroe Islands.
Other forms of the name include:
- Billan (Swedish)
- Bille (Swedish)