Holly Grove is a city in Monroe County, Arkansas, United States. As of the 2020 census, the city population was 460, down from 602 in 2010. T…Holly Grove is a city in Monroe County, Arkansas, United States. As of the 2020 census, the city population was 460, down from 602 in 2010. The town started as a plantation community which was a suburb of Lawrenceville, which was the seat of Monroe County until 1857. However, the construction through Holly Grove in 1872 of the Arkansas Central Railway, later the Arkansas Midland Railroad, caused Lawrenceville to shrink and Holly Grove to grow. The town was officially incorporated in 1876.