Energy (from Greek ἐνέργεια "operation, activity") may refer to
- in physics, Energy, a scalar quantity measured in Joule
- Energy (society), energy resources, fuels, electricity and associated technologies
- Work (thermodynamics)
- Heat
- Energy (signal processing), the energy Es of a continuous-time signal x(t)
- in Aristotelism, Energeia, the general principle of "activity", both physical and metaphysical
- Actus in scholastic philoslphy, see Actus et potentia
- Essence-Energies distinction
- Energy (psychological), the energy that powers mental processes
- Energy (spirituality), a putative all-pervasive spirit
- Energy medicine, one of five domains of complementary and alternative medicine
In toponymy
- Energy, Illinois, a village in the USA
- Energy, Texas, a settlement in the USA
In music
- Energy (album), an album by Operation Ivy
- Energy (band), a Taiwanese boy group
- Energy Rekords, a record label
- "Energy", a song by The Pillows from Pantomime
- "Energy", a song by The Apples in Stereo from New Magnetic Wonder
- "Energy", a song in the LazyTown soundtrack
- Energy (Keri Hilson Song), a song by Keri Hilson
In radio stations:
- KNGY, Energy 92.7, San Francisco, California, USA
- KNRJ, Energy 92.7 & 101.1, Phoenix, Arizona, USA
- KBZD, Energy 99.7, Amarillo, Texas, USA
- NRJ Radio, Paris, France