Orac might refer to:
- Orgone accumulator — A device invented by Wilhelm Reich to trap and focus orgone energy
- Respectful Insolence — A blog by a doctor and medical researcher, whose nom de blog is Orac, on medical woo and many other pseudoscience topics. Also one of the contributors to ScienceBlogs.
- Oxygen Radical Absorbance Capacity, which is what antioxidants have
- A fictional computer from the science fiction television series Blake's 7, an article on which (or whom, as it is theoretically Turing-test compliant) can be found here.