The town was first mentioned in the second half of the 13th century, although the name Krtíš first appeared in 1245 under name Curtus (Latin). Until 1919 it was the part of the Hungarian Kingdom, later Austria-Hungary, part of the Nograd – Novohrad region. It was ruled by Ottoman Empire between 1554 and 1594 and again between 1596 and 1686 as part of Filek sanjak, its centre was Rim Sonbat. After Treaty of Trianon it became part of Czechoslovakia. In the Second World War, the village remained in the Slovak state, a Nazi-Germany ally. The village suffered damages in the spring of 1945 when the Soviet army of the 2nd Ukrainian front together with the Romanian army met the Nazi Germany units. A Romanian military cemetery can be found in the nearby Modry Kamen. The village developed to a town in the 1960s with the opening of the mine for brown coal.
Veľký Krtíš lies at an altitude of 200 metres (656 ft) above sea level and covers an area of 15.028 square kilometres (5.8 sq mi). It is situated in the Krupinská planina, at the foothills of Javorie, around 15 kilometres (9 mi) north of the Hungarian border and around 75 kilometres (47 mi) south of Banská Bystrica.