| Hajnáčka | |
| Settlement Type: | Village |
| Subdivision Type: | Country |
| Subdivision Name: |  Slovakia |
| Subdivision Type2: | Region |
| Subdivision Name2: | Banská Bystrica |
| Subdivision Type3: | District |
| Subdivision Name3: | Rimavská Sobota |
| Pushpin Map: | Slovakia Banská Bystrica Region#Slovakia |
| Pushpin Relief: | 1 |
| Coordinates: | 48.2167°N 77°W |
| Established Title: | First mentioned |
| Established Date: | 1245 |
| Area Total Km2: | 25.66[1] |
| Area Total Sq Mi: | 9.91 |
| Elevation M: | 224[2] |
| Elevation Ft: | 735 |
| Population Total: | 1139[3] |
| Population Density Km2: | 44.37[4] |
| Population Density Sq Mi: | 17.13 |
| Postal Code Type: | Postal code |
| Postal Code: | 980 33 |
| Area Code: | +421 47 |
| Blank Name: | Car plate |
| Blank Info: | RS |
Hajnáčka (formerly: Slovak: Hajnacžka; German: Hajnatschko; Hungarian: Ajnácskő) is a village and municipality in the Rimavská Sobota District of the Banská Bystrica Region of southern Slovakia.
In historical records the village was first mentioned in 1245 as Danuskue (1255 Kues, 1344 Anyaskw; the name comes from Slavic "Hajnáč") when a big castle stood here. The village developed from the farmyard under the castle. It was always the seat of important feudal lords. In 1545 it was besieged by Turks. During the Turkish times the village was abandoned. In 1773 there were only 13 peasant farmers and some craftsmen living in the village. In 1828 there were 84 houses and 375 inhabitants. These people mainly lived from agriculture till 1945. From 1938 till 1944 Hajnáčka was part of Hungary.
Historical monuments in Hajnáčka include:
The records for genealogical research are available at the state archive "Statny Archiv in Banska Bystrica, Slovakia"