Katosan is a town and former princely state in Gujarat, western India.
The town is in Mahesana Taluka.
Katosan was a Fourth Class princely state and taluka, comprising five more villages, covering ten square miles in Mahi Kantha, ruled by Hindu Koli Chieftains.
It had a combined population of 5,510 in 1901, yielding a state revenue of 26,617 Rupees (some three quarters from land), paying a tribute of 4,893 Rupees to the Gaikwar Baroda State, supplemented by fixed tribute sums for Baroda from individual villages belonging entirely to Katosan state : 430 Rupees from Nadasa, 623 Rupees from Jakasna, 96 Rupees from Ajabpura, 139 Rupees from Gamanpura and 3,580 Rupees from Jotana.
Furthermore, Katosan was also the seat of Katosan Thana.
On 1 February 1940, Katosan ceased to exist, being among the princely states merging under the 'Attachment Scheme' into the Gaekwar Baroda State, following its fate into independent India's Bombay State and after its split Gujarat.