From the Roman clan name Porcius; famously used by Shakespeare in The Merchant of Venice.
Portia is a name of Latin origin, derived from the ancient Roman gens Porcia — the Porcian clan — whose most famous member was Cato the Younger, the Stoic philosopher and senatorial opponent of Julius Caesar. The clan name itself is thought to derive from the Latin porcus (pig), a common totem for ancient Roman families, though the association lost its barnyard quality over centuries of aristocratic use. The historical Porcia Catonis, daughter of Cato and wife of the Roman senator Brutus, is one of antiquity's more remarkable figures: she reportedly wounded herself in the thigh to prove to her husband that she could bear pain and keep secrets — a test of worthiness before he revealed his role in the conspiracy against Caesar.
She appears in Shakespeare's Julius Caesar as a figure of urgent, contained intelligence. It is Shakespeare's other Portia, however, who defines the name for most readers: the heroine of The Merchant of Venice, a brilliant, wealthy heiress who disguises herself as a lawyer named Balthazar to defend Antonio in court. Her speech beginning 'The quality of mercy is not strained' is among the most quoted passages in the English language, and Portia herself is one of Shakespeare's most intellectually formidable female characters — witty, strategic, and in command of every room she enters.
The name has carried this association with eloquence, legal acuity, and quick-minded femininity for four centuries. In modern usage, Portia has remained an elegant choice, neither overused nor obscure. It is perhaps best known today through the Australian actress Portia de Rossi, who brought a dry comic precision to her roles in Arrested Development and Ally McBeal. The name sits comfortably in the register of classical choices that feel simultaneously timeless and distinctive.