Polonia Sanz y Ferrer (died 1892) was a Spanish dentist, the first qualified woman to practice dentistry in Spain.
On 10 April 1849 she was issued a license by the Academy of Medicine and Surgery in Valencia, which was confirmed after an examination on 20 December 1849, to practice dentistry, such as "clean teeth, remove teeth [...] and other operations practiced by dentists".
She was met with great resistance from male colleagues, and was forced to defend herself in public.
She was not able to achieve her ambition to be appointed honorary dentist to the Spanish court.
Her predecessor María Rajoó, who practiced as a dentist in Madrid in 1800–1830, was not licensed as she was.