The Antonovo municipality is situated in Northeast Bulgaria, in the southwest part of the District of Targovishte. It borders the municipalities of Popovo, Targovishte and Omourtag (the District of Targovishte) to the north, northeast and east; the Kotel municipality (the District of Sliven) to the southeast; the municipalities of Elena, Zlataritsa and Strazhitsa (the District of Veliko Tarnovo) to the southwest and northwest. It occupies an area of 472 km2. The municipality's whole territory is situated in the Fore Balkan. It encompasses the low-mountain area Slannik, the Antonovo Elevations and the valleys of the rivers Golyama Reka and Stara Reka.