Svilaja is a mountain range in Croatia, located in inland of Dalmatian Zagora.
It belongs to Dinaric Alps, and it stretches from the town of Sinj northwest to the Petrovo field, approximate 30 km in length.
The highest peak is Svilaja or Bat at 1508 m.a.s.l. Some of other northwest peaks are Jančak (1483 m), Kita (1413 m), Turjača (1340 m) and Lisina (1301 m) over the town of Vrlika.
From nearest mountain cliff Veliki Kozjak (1207 m), which is northwest continuation of Svilaja, it is separated with the "lower saddle" Lemeš (860 m) above village of Maovice.
Some parts of mountain are dangerous, because of mines left during the Croatian War of Independence.