Ilova is a river in central Croatia, a left tributary of Lonja-Trebež. It is 85 kilometres (53 mi) long and its basin covers an area of 1,049 square kilometres (405 sq mi).
Ilova rises in the hilly areas of eastern Bilogora, south of Virovitica and Suhopolje, and flows towards the southwest, forming a series of lakes near Veliki Zdenci. It turns to the south near Garešnica, where there are another set of lakes at the confluence with the river Toplica that rises in Papuk. It then turns westward to pass near the eponymous village of Ilova south of Kutina, and then flows into the Trebež in the northern part of Lonjsko Polje nature park.