Alessi is a modern short form of Alessia or Alessandra, the Italian forms of Alexis and Alexandra, and so means "defender" or "protector of mankind"; it is also a familiar Italian surname. The name appeared out of nowhere in American statistics: outside the top 9,000 in 2019, it leapt to number 2,851 in 2020 and number 1,563 in 2021, its peak, and has since eased to number 2,694 in 2025 with 64 births.