Thanjavur district is in the east coast of Tamil Nadu. The district lies between 78° 45’ and 70° 25′ of the Eastern longitudes and 9° 50′ and 11° 25′ of the Northern Latitudes.. Thanjavur is situated in the Cauvery delta, at a distance of 314 km (195 mi) south-west of Chennai and 56 km (35 mi) east of Tiruchirappalli. The District is bound by Coloroon on the North which separates it from Ariyalur and Tiruchirapalli district; Thiruvarur and Nagapattinam districts on the east; Palk Strait and Pudukottai on the South and Pudukottai and Tiruchirapalli on the West.

The nearest seaport is Nagapattinam which is 84 km (52 mi) east of Thanjavur. The nearest airport is Tiruchirapalli International Airport, located at a distance of 56 km (35 mi). The city has an elevation of 57 m (187 ft) above mean sea level. The area of the district isn 3396.57Sq.Km