The major occupation of the inhabitants of the town is tourism and service oriented industry, while the traditional occupation is agriculture.Thanjavur is known as the "Rice bowl of Tamil Nadu". Paddy is the crops and the other crops grown are Blackgram, Banana, Coconut, Gingelly, Ragi, Red gram, Green gram, Sugarcane and Maize. The total percentage of land fit for cultivation is 58%. There are three seasons for agriculture in Thanjavur – Kuruvai (June to September), Samba (August to January) and Thaladi (September, October to February, March). The total rice production has been maintained at 10.615 L.M.T and 7.077 L.M.T. The town acts as a focal point for food grains transported from the adjoining areas of the Cauvery Delta. Organic farming is gradually being known to the farmers of Thanjavur. In order to maximize agricultural produce organic farming is being implemented. Though agriculture is the main economic activity, only 7% of the population is involved in it. There is a lot of agricultural related trading that forms the key economic activity in the town.
Thanjavur is an important centre of silk weaving in Tamil Nadu. There were 200 silk weaving units in the town in 1991 with around 80,000 people working in them. The sarees produced in the villages surrounding Thanjavur are sold in Thanjavur and neighbouring towns. Increasing production costs and competition from large-scale producers have reduced the number of people involved in the production. The town produces bell metal craft like Thanjavur metal plates, bronze images bowls, napkins and powder boxes made of copper and bronze. The town is a major manufacturer of pith works consisting of models of Hindu idols, mosques, garlands and other bird figurines. Manufacture of musical instruments like veena, tambura, violin, mrithamgam, thavil and kanjira is another economic activity in the town.
All major nationalized banks such as State Bank of India, Indian Bank, Central Bank of India, Punjab National Bank, Indian Overseas Bank and private banks like ICICI Bank, City Union Bank have their branches in Thanjavur. All these banks have their automated teller machines located in various parts of the town.