Obthorpe is a hamlet in the civil parish of Thurlby, in the South Kesteven district of Lincolnshire, England. It lies 3 mi south from Bourne, 6 mi north-east from Stamford and less than 1 mi west from the A15. Thurlby is the nearest village, 1 mi to the north. The house known as Obthorpe Lodge lies about 1 mile due east from the hamlet; both are on the Macmillan Way footpath. Obthorpe is mentioned in the Domesday account as "Opetorp". The manor comprised 19 households and 17 freemen, and had a meadow and woodland, both of 20 acre. Lordship in 1066 was held by Ulf Fenman, transferred to Gilbert of Ghent in 1086, who was also Tenant-in-chief.