Rantau Panjang (Kelantanese: Ghata Panje; Jawi: رنتاو ڤنجڠ; Thai: รันเตาปันจัง) is a mukim (subdistrict/commune) and also a parliamentary constituency in Pasir Mas District, Kelantan, Malaysia, located next to the Thai border.

The town of Su-ngai Kolok is situated adjacent to Rantau Panjang, right across the Golok River. Both towns are linked via the Rantau Panjang-Sungai Golok Bridge, popularly known as the Harmony Bridge (Malay: Jambatan Muhibbah).

Along with Pengkalan Kubor on the South China Sea coast, Rantau Panjang is a popular place for duty-free shopping.