The Promontory Mountains are a range in Box Elder County, Utah.

The southern portion forms a cape extending 20 miles (32 km) south into the Great Salt Lake.

The First transcontinental railroad was completed with the Golden Spike just north of the range at Promontory Summit in the Utah Territory.

Today, trains cross the Promontory Point at the southern tip of the range via the Lucin Cutoff railroad causeway across the lake.

The west side of the range is bounded by the East Great Salt Lake normal fault which passes under the lake along the west side of Antelope Island and on to the south shore of the lake to the west side of the Oquirrh Mountains where it continues on strike as the Oquirrh Fault.