Ljuljaci () is a village located in the Kniàmunicipality in the à  umadija District, Serbia. According to the 2002 census there was 369 people inhabiting the village, in 1991 the number was 475.
Dragoslav SrejoviÃÂ, a famous Serbian archaeologist and academic traces his family origin (SrejoviÃÂi) to this village, he has organized the excavations of the prehistoric Bronze Age tumuli which he defined of the Racha-Ljuljaci cultural group, a local variant of the Vatin culture. Triballi (Thracian) tombs have been found on the site. The village is a former gradina.