Clelia Grillo Borromeo Arese (1684 – 23 August 1777[1]) was an Italian (Genoese) natural philosopher,[1] mathematician and scientist.

She was born in Genoa, the daughter of Marcantonio Grillo, duke of Mondragone, and Maria Antonia Imperiali.

The most frequent visitor to the salon of the Countess was Antonio Vallisneri, physician, naturalist and Professor of medicine at the University of Padua.

In 1719 she founded the Clelian Academy (Academia Clœlia Vigilantium), whose members gathered in her palace in Milan.

Prominent members included the Abbot Luigi Guido Grandi, Jesuits and distinguished mathematicians Tommaso Ceva and Giovanni Girolamo Saccheri, the physicists Giovanni Francesco Crivelli (fellow of the Royal Society, proponent of the equal importance of theoretical physics with experimental physics) and Alessandro Volta and the scholars Francesco Saverio Quadrio and Giuseppe Antonio Sassi.

[3] In 1728, Luigi Guido Grandi described the so-called Clelia curves in his book Flores geometrici ex rhodonearum et cloeliarum, which he dedicated to Borromeo.