The word Clackamas may refer to:
- Clackamas people, a Native American people in what is now Oregon
- The now extinct language spoken by the tribe, one of the Chinookan languages
Named after tribe
- The Clackamas River, a tributary of the Willamette River in northwestern Oregon
- Clackamas County, Oregon
- Clackamas, Oregon, a community in Clackamas County
- Clackamas High School in Clackamas, Oregon
- Clackamas Community College in Oregon City, Clackamas County
- The North Clackamas School District in Clackamas County
- Clackamas iris or Iris tenuis
- "Clackamas", a codename for Intel's 64-bit processor technology