'Louisa' originates from French, specifically the word 'Louise', where the Old High German roots 'hlūd' meant 'fame' and 'wīg' meant 'warrior'.

'Louisa' changed from the Old French form 'Louise', itself derived via Latinized forms such as 'Ludovicus' from Old High German 'Hludwig', and eventually became the modern English name 'Louisa'.

Initially, it meant 'famous in battle' (from the Germanic elements), but over time it evolved into its current use as a female personal name without a literal descriptive meaning.