Its area was defined in the Victoria Constitution Act of 1855 as: "Bounded on the West by the River Avoca, from its Source in the great dividing Range to its Entrance to Lake Bael Bael, thence by a Line Northward to the River Murray ; on the North by the River Murray ; on the East by the River Campaspe to its Junction with the Coliban, and on the South by the Northern Boundary of the Counties of Dalhousie and Talbot to the commencing Point, excepting the Country comprised in the Electoral Districts of the Castlemaine Boroughs and of the Sandhurst Boroughs."[3]
The district of Loddon was one of the initial districts of the first Victorian Legislative Assembly, 1856.[4]
Loddon was abolished in the redistribution of 1859, parts of the former Loddon district were incorporated into Castlemaine and the new electoral districts of Maldon and Mandurang.[5]