Prithvi Raj III, commonly known as Prithviraj Chauhan (1149–1192 CE), is a king of the Hindu Chauhan (Chauhamana) dynasty, who rules the kingdom of Ajmer and Delhi in northern India during the latter half of the 12th century.

Prithviraj Chauhan belongsto the Rajput Chauhan clan.

Chauhan was the last independent Hindu king, before Hemu, to sit upon the throne of Delhi.

He succeeds to the throne in 1169 at the age of 20, and rules from the twin capitals of Ajmer and Delhi which he had received from his maternal grandfather Arkpal or Anangpal III of the Tomara dynasty in Delhi.

He controls much of present-day Rajasthan and Haryana, and unifies the Rajputs against Muslim invasions.

His elopement in 1175 with Samyukta (Sanyogita), the daughter of Jai Chandra Rathod, the Gahadvala king of Kannauj, is a popular romantic tale in India, and is one of the subjects of the Prithviraj Raso, an epic poem composed by Chauhan's court poet and friend, Chand Bardai.

Prithviraj Chauhan defeats the Muslim ruler Shahabuddin Muhammad Ghori in the First Battle of Tarain in 1191 and sets him free as a gesture of mercy.

Ghauri attacksd for a second time the next year, and Prithviraj is defeated and captured at the Second Battle of Tarain (1192).

Sultan Ghauri takes Prithviraj to Ghazni and blins him.

Legend states that in an archery demonstration, Prithviraj's poet Chand Bardai gave him the physical location of Ghori in the arena via poem and then, as Ghori ordered the start of show, Prithviraj shot him dead with a Shabdbhedi-baan.

After his defeat, Delhi came under the control of Muslim rulers.