Harju may refer to:
Geography
Estonia Harju County, one of 15 counties of Estonia Harju, Hiiu County, a village in Hiiumaa Parish, Hiiu County. Pühalepa-Harju, a village in Hiiumaa Parish, Hiiu County, formerly known as Harju.
Harju Bay, a bay in Saaremaa Parish, Saare County
Harju Street, a street in Pärnu
Finland Harju, Helsinki, a quarter of Helsinki
Other uses Harju (surname) Harju Elu, local newspaper of Harju County