Petraitis is the masculine form of a patronymic Lithuanian family name. Its feminine forms are: Petraitienė (married to or widow of Petraitis) and Petraitytė (unmarried woman, daughter of Petraitis).
Notable people with the surname include:
- Julius Petraitis (born 1905, date of death unknown), Lithuanian long-distance runner
- Vikki Petraitis (born 1965), Australian true crime author