The Luni is an endorheic river of western Rajasthan state, India. It originates in the Pushkar valley of the Aravalli Range, near Ajmer, passes through the southeastern portion of the Thar Desert, and ends in the marshy lands of Rann of Kutch in Gujarat, after travelling a distance of 495 km. It is first known as Sagarmati, then after passing Govindgarh, it meets its tributary Sarsuti, which originates from Pushkar Lake, and from then on it gets its name Luni.
In 1892, Maharaja Jaswant Singh of Jodhpur constructed Jaswant Sagar in Pichiyak village between Bilara and Bhavi of Jodhpur district. It is one of the largest artificial lakes in India, and irrigates more than 12,000 acres (49 km2).
The Luni is also known as the Lavanavati, which means "salt river" in Sanskrit, due high salinity of its water.
The Luni River basin is 37,363 km², which includes all or part of the Ajmer, Barmer, Jalore, Jodhpur, Nagaur, Pali, and Sirohi districts of Rajasthan and the Banaskantha and Patan districts of northern Gujarat. Its major tributaries are the Sukri, Mithri, Bandi, Khari, Jawai, Guhiya and Sagi from the left, and the Jojari River from the right.