Hajnáčka (formerly: 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.

In 1773 there were only 13 peasant farmers and some craftsmen living in the village.

Historical monuments in Hajnáčka include: The records for genealogical research are available at the state archive "Statny Archiv in Banska Bystrica, Slovakia"

This article about a location in the Rimavská Sobota District of Slovakia is a stub.