Osian (also spelt Osiyan) is an ancient town located in the Jodhpur District of Rajasthan state in western India. It is an oasis in the Thar Desert. The town is a panchayat village and the headquarters for Osian tehsil. It lies 69 km (43 mi) by road north of the district headquarters at Jodhpur, on a diversion off the main Jodhpur – Bikaner Highway. The under-construction Amritsar Jamnagar Expressway passes through this town.

Osian is famous as home to the cluster of ruined Hindu and Jain temples dating from the 8th to 12th centuries. The city was a major religious centre of the kingdom of Marwar during the Gurjara Pratihara dynasty. Of the 18 shrines in the group, the Surya Temple, Sun Temple, Sachiya Mata Temple and the Jain temple dedicated to Mahavira stands out in their grace and architecture.

The town was a major trading center at least as early as the Gupta period. It maintained this status, while also being a major center of Hinduism and Jainism for hundreds of year. This came to an abrupt end when the town was attacked by the armies of Muhammed of Ghor in 1195.