埃塞克斯郡（英语：Essex，英国英格兰东部的郡。以人口计算，滨海绍森德是第1大镇（Town）、第4大区（district），切尔姆斯福德是第2大镇（亦是郡治），科尔切斯特是第3大镇，巴西尔登是第4大镇；科尔切斯特区是第1大区，巴西尔登区是第2大区。

把埃塞克斯郡看待成34个非都市郡之一，它包含12个非都市区，占地3,465平方公里（第11），有1,361,200人口（第11）；看待成48个名誉郡之一，它包含多2个单一管理区─瑟罗克、滨海绍森德，占地增至3670平方公里（第11），人口增至1,670,000（第6）。

Essex /ˈɛsᵻks/ is a county in England, immediately north-east of London. It borders the counties of Suffolk and Cambridgeshire to the north, Hertfordshire to the west, Kent across the estuary of the River Thames to the south and London to the south-west. The county town is Chelmsford, which is the only city in the county. Essex occupies the east of the pre-England Kingdom of Essex. As well as rural areas, the county also includes the Lakeside Shopping Centre, London Stansted Airport and the new towns of Basildon and Harlow.