The Athabasca Oil Sands (also known as the Athabasca Tar Sands) are large deposits of bitumen, or extremely heavy crude oil, located in northeastern Alberta, Canada. These oil sands consist of a mixture of crude bitumen (a semi-solid form of crude oil), silica sand, clay minerals, and water. The Athabasca deposit is the largest reservoir of crude bitumen in the world and the largest of three major oil sands deposits in Alberta, along with the nearby Peace River and Cold Lake deposits. Together, these oil sand deposits lie under of sparsely populated boreal forest and muskeg (peat bogs) and contain about of bitumen in-place, comparable in magnitude to the world's total proven reserves of conventional petroleum.

With modern non-conventional oil production technology, at least 10% of these deposits, or about were considered to be economically recoverable at 2006 prices, making Canada's total oil reserves the second largest in the world, after Saudi Arabia's. The Athabasca deposit is the only large oil sands reservoir in the world which is suitable for large-scale surface mining, although most of it can only be produced using more recently developed in-situ technology.

Category: Image - :Athabasca Oil Sands map.png|thumb|right|The Athabasca Oil Sands in Alberta, Canada.