The Siletz are a nearly extinct tribe of Native Americans from Oregon. Siletz may also refer to:

• Confederated Tribes of Siletz Indians, a federally recognized tribal entity from the U.S. state of Oregon.

• Siletz Reservation, an Indian reservation in Oregon, home to the Confederated Tribes of Siletz

• Siletz Bay, a body of water in Oregon.
• Siletz, Oregon, a city in Oregon.
• Siletz River, a river in Oregon.
• Siletz River Volcanics, a formation of Eocene volcanic deposits on the Oregon coast.
• Siletz terrane: Siletzia, a tectonic terrane that forms the geological basement under northwestern Oregon, southwestern Washington (state), and the southern tip of Vancouver Island.