Galilei is a surname, and may refer to:
- Galileo Galilei (1564–1642), astronomer, philosopher, and physicist.
- Vincenzo Galilei (1520–1591), composer, lutenist, and music theorist; father of Galileo
- Michelagnolo Galilei (1575–1631), Baroque lutenist and composer, brother of Galileo
- Alessandro Galilei (1691–1736), Florentine mathematician and architect
Two craters have been named for Galileo Galilei, with a different spelling:
- Galilaei (lunar crater), on the Moon
- Galilaei (Martian crater), on Mars