Fios may refer to:
- Fíos, a parish in Parres, Spain
- Verizon Fios, bundled home communications service offered by Verizon Communications in the US
- FiOS from Frontier, the former name for Frontier FiberOptic, a bundled home communications service offered by Frontier Communications in the US
- FiOS1, a defunct news-based pay television network carried by Verizon Fios in the New York metropolitan area
- FIoS, after a name denotes Fellow of the Institute of Swimming