Oslava is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in the Czech Republic

Czech Republic

The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

, the left tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Jihlava River. It originates in the Bohemian-Moravian Highlands

Bohemian-Moravian Highlands

The Bohemian-Moravian Highlands is an extensive range of hills and low mountains over long, which runs in a northeasterly direction across the Czech Republic and forms the border between Bohemia and Moravia...

 (Českomoravská vrchovina) upland at the elevation of 567 m and flows for 99.2 km to Ivančice

Ivancice

Ivančice is a town in the South Moravian Region of the Czech Republic, 21 km south-west of Brno. The town has approximately 9,300 inhabitants. It lies on the confluence of Oslava , Jihlava and Rokytná rivers.-History:...

, where it enters the Jihlava River.

It flows through numerous towns and villages, including Nové Veselí

Nové Veselí

Nové Veselí is a small town in Žďár nad Sázavou District in the Vysočina Region of the Czech Republic.The town covers an area of , and has a population of 1,238 ....

, Ostrov nad Oslavou

Ostrov nad Oslavou

Ostrov nad Oslavou is a small town in Žďár nad Sázavou District in the Vysočina Region of the Czech Republic.The town covers an area of , and has a population of 892 ....

, Velké Meziříčí

Velké Mezirící

Velké Meziříčí is a town in the Vysočina Region, Czech Republic. It is situated under the original Gothic castle in a valley framed by the hills of the Bohemian-Moravian Highlands....

, Náměšť nad Oslavou

Námešt nad Oslavou

Náměšť nad Oslavou is a town in the Vysočina Region of the Czech Republic. It has around 5,200 inhabitants.The town is known for "Little Charles Bridge", which is a smaller replica of the Charles Bridge in Prague. Náměšť nad Oslavou Castle is located on a neighbouring hilltop above the...

, Oslavany

Oslavany

Oslavany is a town in the South Moravian Region of the Czech Republic. It has around 4,600 inhabitants....

 and Ivančice

Ivancice

Ivančice is a town in the South Moravian Region of the Czech Republic, 21 km south-west of Brno. The town has approximately 9,300 inhabitants. It lies on the confluence of Oslava , Jihlava and Rokytná rivers.-History:...

. The Mostiště Dam is constructed on the river.

Its longest tributaries are the Balinka and Chvojnice rivers.