Flathead may refer to:
- Flat-head screwdriver, a screwdriver designed to turn slotted screws
- Flat-head screw, a screw with a flat top, designed to be installed in a countersunk hole
- Flathead engine, a valve configuration
- The Flathead, or Flathead Indian (or Flathead Amerindian) tribe more formally known as the Confederated Salish and Kootenai Tribes of the Flathead Nation
- The Choctaw, a southeastern Native American group also known by the name of the Flatheads
- Platycephalidae, a family of fish
- Flathead (fish), various species of fish in this family
- Positional plagiocephaly, a medical syndrome
- The song "Flathead", or the "Flathead" EP, by The Fratellis
- The ruling family of the Great Underground Empire, the location of the Zork adventure game series, most notably in Zork Zero