Municipality of the County of Antigonish, Administrative county in Nova Scotia, Canada

The Municipality of the County of Antigonish is an administrative county covering coastal areas, forests, and agricultural lands in eastern Nova Scotia. The jurisdiction encompasses natural reserves, educational institutions, and provides public services through its administrative infrastructure.

Sydney County was created in 1784, and the settlement of St. Mary's, founded in 1818, was split between Sydney and Halifax counties until its Halifax portion was joined to Sydney in 1822. Sydney shrank in 1836 when Guysborough County was carved out, and in 1863 the remaining county was renamed Antigonish. The province incorporated it as a county municipality in 1879, and the town of Antigonish became a separate municipality ten years later.

The Mi'kmaq name Antigonish is of uncertain meaning; one suggested source is Nalegitkoonecht, "where branches are broken off", from bears breaking branches to reach beech nuts. The county carried the name Sydney until 1863, when it was renamed Antigonish.

The county surrounds the separate Town of Antigonish and excludes the Pomquet and Afton 23 and Summerside 38 reserves. Highway 104 and routes 4, 7 and 16 cross it, so a car is needed to reach coastal parks such as Pomquet Beach and the inland Beaver Mountain park.

Antigonish County was called Sydney County until 1863, when the name changed to Antigonish. In 2001 the town of Antigonish sought to annex 1,600 hectares of the surrounding county; the municipality opposed it, and a 2005 plebiscite saw 84% of municipal voters back amalgamation while 74% of town voters rejected it.