The Porcupine Gold Rush was a gold rush that took place in Northern Ontario starting in 1909 and developing fully by 1911. A combination of the hard rock of the Canadian Shield and the rapid capitalization of mining meant that smaller companies and single-man operations could not effectively mine the area, as opposed to earlier rushes where the gold could be extracted through placer mining techniques. Although a number of prospectors made their fortune, operations in the area are marked largely by the development of larger mining companies, and most people involved in the mining operations were their employees.
The mines peaked between the 1940s and the 1950s but still continue to produce gold although the many smaller mines have been consolidated into a small number of larger holdings. By 2001, 67 million troy ounces of gold have been mined from the Porcupine area, making it by far the largest gold rush in terms of actual gold produced. For comparison, the well-known Klondike Gold Rush produced about 12 million troy ounces.
The Porcupine rush, along with the Cobalt Silver Rush and Kirkland Lake Gold Rush, all in the early 20th century, drove most of the settlement effort in northern Ontario.