Pictou County is a county in the Canadian province of Nova Scotia. It was established in 1835, and was formerly a part of Halifax County from 1759 to 1835. It had a population of 45,643 people in 2011, which represents a decline of 1.9 percent from 2006. Furthermore, its 2011 population is only 91.93% of the census population in 1991. It is the sixth most populous county in Nova Scotia.