Zajączkowski is a Polish surname and can refer to:
Andrzej Zajączkowski (1922–1994, Warsaw), a Polish sociologist, culture anthropologist, Africanist
Bolesław Zajączkowski (d. 1920), a Polish lawyer and reserve officer of the Polish Army
Grzegorz Zajączkowski (born 1980), a Polish sprinter
Władysław Zajączkowski (1837–1898), a Polish mathematician