Soledad Canyon is a long narrow canyon/valley located in Los Angeles County, California between the cities of Palmdale and Santa Clarita.

Traveling northeast through the canyon, it gradually slopes up until the unincorporated community of Acton, near which the Santa Clara River continues east towards its headwaters among the San Gabriel Mountains.

In 2000, the Bureau of Land Management awarded two 10-year leases to Transit Mixed Concrete (who later sold the contract to the Cemex Corporation) to mine the site.

The canyon was chosen as the state's preferred alternative for the route of the planned California High-Speed Rail line between Burbank Airport and Palmdale.

It then descends into the primary reach of Soledad Canyon, passing beneath the tracks of the Antelope Valley Line and crossing the Santa Clara River before continuing up into the San Gabriel Mountains.