Giacomo Girolamo Casanova de Seingalt (April 2, 1725 – June 4, 1798) is an Italian adventurer and author from the Republic of Venice.

His autobiography, Histoire de ma vie (Story of My Life), is regarded as one of the most authentic sources of the customs and norms of European social life during the eighteenth century.

As was not uncommon at this time, Casanova, depending on circumstances, uses more or less fictitious names, such as baron or count of Farussi (the name of his mother) or Chevalier de Seingalt (pronounced Saint-Galle, as in French).

He often signs his works Jacques Casanova de Seingalt after he begins writing in French following his second exile from Venice.

He will become so famous for his often complicated and elaborate affairs with women that his name is today synonymous with "womanizer".

He associates with European royalty, popes and cardinals, along with luminaries such as Voltaire, Goethe and Mozart.

He spends his last years in Bohemia as a librarian in Count Waldstein's household, where he also writes the story of his life.