The civil parish has an area of 5.72 square kilometres (2 sq mi), part of which is in The Broads National Park.

The other neighbouring parishes are Thurne to the north-west, Repps with Bastwick to the north, Rollesby to the north-east and Clippesby to the east.

A group of eight ring ditches in the north of the parish have been interpreted as a ploughed-out Bronze Age round barrow cemetery.

[4] Back then, the area was part of an island -the Isle of Flegg, which was surrounded by shallow sea and salt marsh.

[4] The substantial Anglo-Saxon villages of Ashby and Oby were listed in the Domesday Book as Ascheby and Obei, and were in the West Flegg Hundred.

King Canute had donated these landholdings to the abbey, which retained possession until the Dissolution when they passed to the Bishop of Norwich.

[12] Ashby church was intact in around 1740, when the Norfolk antiquarian Francis Blomefield visited and left a brief description which he had published in 1810.

In 1790, there was a land transaction which involved the churchyard being given into secular ownership,[13] William Faden published a map of Norfolk in 1797, which also indicated that the church was out of use by then.

An ancient area of common land attached to Asbby was lost, and the poor people of the township were compensated with the income from three acres (1.2 hectares) which was fetching £6 in the 1850s (£600 in 2021 values).

[19] The township of Ashby and Oby became a civil parish under the Local Government Act 1894, part of the East and West Flegg Rural District.

[21] The only public amenity consists of a post box at the west end of Boundary Road, opposite the entrance to Harrison’s Farm Lane.

Two short canals, called ‘’dikes’’ but not simply drainage ditches, run off the river and originally gave boat access to farmsteads.

[25] It was located at Oby Manor Farm, where there is a 17th-century barn which is now single-storey with a modern roof but which has apparently been cut down from a taller building.

Later in the Middle Ages, the chancel was substantially extended to form a three-bay square-ended and buttressed structure as wide as the nave.

An area of black and yellow floor tiling, laid in a zig-zag pattern "similar to those used in Martham church, only smaller" was uncovered.

[28] The Norfolk antiquarian Francis Blomefield visited in about 1740 when the church was still standing, and left a brief description which did not include architectural details.

[29] Grave-slabs in the chancel: ‘’Orate pro anima Williami Clypesby, Armigerii, qui obit 2 die Julii 1455."