Costanza Farnese (December 19, 1500 in Rome – May 23, 1545 in Rome) was a daughter of Alessandro Farnese and Silvia Ruffini, born before her father became Pope Paul III. Her siblings were Pier Luigi, Paul, Ranuccio and Lucrezia.
She married Bosio II Sforza, count of Santa Fiora e Cotignola, and her children include:
- Guido Ascanio
- Alessandro Sforza
- Sforza Sforza, whose children were Francesco Sforza was Costanza Sforza.
- Faustina Sforza
- Francesca Sforza
- http://gw.geneanet.org/favrejhas?lang=it&p=costanza&n=farnese. Missing or empty