Pikkjärv ('long lake' as noun) or Pikkjärve ('long lake' as genitive) are Estonian-language toponyms:
- Karula Pikkjärv, lake in Valga County
- Kõnnu Pikkjärv, lake in Ida-Viru County
- Viitna Pikkjärv, lake in Lääne-Viru County
- Pikkjärve, Jõgeva County, village in Jõgeva Parish, Jõgeva County
- Pikkjärve, Valga County, village in Valga Parish, Valga County