Plastic optical fiber (POF) (or Polymer optical fibre) is an optical fiber that is made out of polymer. Similar to glass optical fiber, POF transmits light (for illumination or data) through the core of the fiber. Its chief advantage over the glass product, other aspect being equal, is its robustness under bending and stretching. Optical fiber used in telecommunications is governed by European Standards EN 60793-2-40-2011.

Traditionally, PMMA (acrylic) comprises the core (96% of the cross section in a fiber 1mm in diameter), and fluorinated polymers are the cladding material. Since the late 1990s much higher performance graded-index (GI-POF) fiber based on amorphous fluoropolymer (poly(perfluoro-butenylvinyl ether) has begun to appear in the marketplace. Polymer optical fibers are typically manufactured using extrusion, in contrast to the method of pulling used for glass fibers.