| Ruby Mountain | |
| Elevation M: | 1895 |
| Prominence M: | 265 |
| Location: | British Columbia, Canada |
| District: | Cassiar Land District |
| Range: | Teslin Plateau (southern Yukon Plateau) |
| Map: | Canada British Columbia |
| Relief: | 1 |
| Label Position: | right |
| Coordinates: | 59.6997°N -133.3686°W |
| Topo Maker: | NTS |
| Type: | Cinder cone |
| Age: | Holocene |
| Volcanic Arc/Belt: | Northern Cordilleran Volcanic Province |
| Last Eruption: | 1898? |
Ruby Mountain, locally known as Old Volcano, is a cinder cone in Stikine Region, British Columbia, Canada, located 23km (14miles) northeast of Atlin and 60NaN0 south of Mount Barham. A recent collapse on the volcano's eastern side created a large landslide which dissects this side of Ruby Mountain. The volcano is the largest feature within the Atlin Volcanic Field.
Reports were received of eruptions in the Ruby Mountain area, about 80abbr=onNaNabbr=on south of Gladys Lake, near the end of the 19th century. Miners working in the area were said to be able to work during the dark nights under the glow of the eruption. However, there has been no evidence found, such as lava flows young enough to have been the site of a historical eruption.