Colchester County is a county in the Canadian province of Nova Scotia.
The appellation Colchester was applied in 1780 to the district previously called Cobequid, and was derived from the town of Colchester in Essex. The old name Cobequid was derived from the Mi'kmaq word "Wagobagitk" meaning "the bay runs far up". The District of Colchester which was at first part of Halifax County was established as county in its own right in 1835.
In 1838 a distinct line of division between Cumberland County and Colchester County was established. Two years later, in 1840, the Township of Parrsboro was divided and part of it annexed to Colchester County. In 1871, the lines between the Counties of Hants and Colchester and between the Counties of Halifax and Colchester were established. In 1880 the boundary between the Counties of Halifax and Colchester was revised. Eventually in 1897 a portion of the boundary between the Counties of Colchester and Cumberland was fixed and defined.
The question of the boundary between Colchester and Cumberland Counties was the subject of a Commission of Inquiry established in 1946. The report was filed in the office of the Provincial Secretary and in the office of the Department of Lands and Forests in January 1959. Certified copies of it were sent to the Registrars of Deeds for the Counties of Colchester, Cumberland and Kings.
Towns in Colchester County are Stewiacke and Truro. Villages include Bible Hill, Brookefield, Tatamagouche, Upper Stewiacke, Five Islands, Debert, Bass River, and Onslow.
Subdivision County Municipalities in Colchester County include A, B and C.
There is one Mi'kmaq First Nations reserve in Colchester County and that is Millbrook.