A title Cumberland was applied by Lieutenant-Colonel Robert Monckton to the captured Fort Beausejour on June 18, 1755 in honour of the third son of King George II, William Augustus, Duke of Cumberland, victor at Culloden in 1746 and Commander in Chief of the British forces. A old Mi'kmaq name for the area was "Kwesomalegek" meaning "hardwood point".

Cumberland County was founded in August 17, 1759. After a Town of Parrsboro was divided inside 1840, a single section was annexed to Cumberl& County and a more section annexed to Colchester.

A dividing line between Cumberl& and Colchester was established around 1840. Within 1897, a part of a mete between the Counties of Colchester & Cumberl& was fixed and defined.

4 towns come located in Cumberland County: Amherst (pop. 9 470), Springhill (pop. Four 091), Parrsboro (pop. One 529), & Oxford (pop. One 332).

Unincorporated communities
Advocate Harbour Amherst Point Apple River Athol Barronsfield Chapman Settlement Chignecto Collingwood Corner Conn Mills Diligent River East Apple River East Mapleton Farmington Fenwick Fort Lawrence Fox Harbour Fox River Fraserville Greenville Station Gulf Shore Halfway River Hansford Harrison Settlement Hastings Head of Amherst Jackson Joggins Kirkhill Kolbec Lakelands Linden Little River Lorneville Maccan Malagash Mansfield Mapleton Minudie Moose River Mount Pleasant Nappan New Canaan New Salem New Yarmouth Northport North Shore Oxford Junction Port Greville Port Howe Port Philip Pugwash Pugwash Junction River Hebert River Philip Rose Salem Sand River Shinimicas Bridge Shulie Southampton South Brook South Victoria Spencers Island Springhill Junction Stonehouse Streets Ridge Thompson Station Tidnish Tidnish Bridge Truemanville Wallace Wallace Ridge Wallace Station Ward's Brook Wentworth Wentworth Centre Wentworth Station West Brook Westchester Station West Leicester Williamsdale Wyvern