Isabella Clara Eugenia (Spanish: Isabel Clara Eugenia) was sovereign of the Spanish Netherlands in the Low Countries and the north of modern France, together with her husband Albert VII, Archduke of Austria. In some sources, she is referred to as Clara Isabella Eugenia. By birth, she was an infanta of Spain and Portugal.
In 1598, Philip II of Spain ceded the Netherlands to his daughter Isabella Clara Eugenia and nephew Albert, who married the next year. They reigned together until his death, when the Netherlands passed to their nephew, Philip IV of Spain, in whose name Isabella Clara Eugenia governed the countries until her death.