At 180 kilometres (110 mi) in length, it is the longest river in Trøndelag county.

The river follows the Orkdalen valley, discharging into the Orkdal Fjord, an arm of the large Trondheimsfjorden, at the town of Orkanger.

Major towns and villages along the river include: Orkanger, Fannrem, Vormstad, Svorkmo, Storås, Meldal, Å (in Orkland Municipality); and Voll and Berkåk (in Rennebu Municipality).

[citation needed] Orkla is a popular river for salmon fishing and the fourth largest in Norway by volume.

The name Orkla (with the diminutive ending -la) originally belonged to the uppermost part of the river (lying in Tynset Municipality, Innlandet), and the meaning of this name is probably "the small part of Ork".