Ghezel Ozan (Persian: قزل اوزن / Qezel Owzan) is one of the longest rivers in Iran, originating from the Chehel Cheshmeh Mountains between Saqqez and Divandarreh in Kurdistan Province flowing in northern Iran.
The Ghezel Ozan headwaters are in the Zagros Mountains, in a region near Divan Darreh in Kurdistan Province. It runs northeastwards through Miyaneh County in East Azarbaijan and then Khalkhal County in Ardabil Province and then Zanjan County and Tarom County in Zanjan Province eastwards through the Alborz mountain range in Gilan Province.
At Rudbar in the southwestern Alborz, it joins the Shah Rud−Shahrood river to form the Sefīd-Rūd river (meaning White River in Persian). Then the Sefid-Rud flows northwards in Gilan Province, through the Alborz range to the Caspian Sea.
Sometimes the Ghezel Ozan and the Sefīd-Rūd are considered as one river, and the words "Ghezel Ozan" and "Sefid-Rud" are used synonymously for the entire river that flows from the Zagros Mountains in Kordestan Province to the Caspian Sea. That definition's full river length is approximately 670 kilometres (420 mi), making it Iran's second longest river after the Karun.
- Microsoft Encarta World Atlas 2001, Microsoft Corporation