Toni is a diminutive of the name Antonia. Antonia originates in Latin language and means "invaluable". It is a feminine form of Antonius. Antonia was the name of numerous figures in Roman history, including the daughter of Marcus Antonius. She was also a Roman Catholic Saint. In the United States it is a fairly popular name. Toni was popularized by the Nobel Prize-winning American author Toni Morrison.