Halifax County (Scottish Gaelic: Siorramachd Halafacs, French: Comté de Halifax) is a county in the Canadian province of Nova Scotia.

The boundaries of four other counties – Annapolis, Kings, Cumberland and Lunenburg – were specifically defined at that time, with Halifax County comprising all the part of peninsular Nova Scotia that was not within their limits.

Following the Seven Years' War, Cape Breton Island was formally annexed to Nova Scotia.

The dividing line between the Districts of Halifax and Colchester was confirmed and established on May 3, 1828.

Eventually in 1880 the boundary between the Counties of Halifax and Colchester was fixed.