An oscillator is a device designed for oscillation.

Oscillator may also refer to:

• Electronic oscillator
  • Voltage-controlled oscillator, used in synthesizers
• Harmonic oscillator
• Oscillator (technical analysis), a method used in technical analysis of financial markets
• Oscillator (cellular automaton)
• Oscillator (EP), an EP by Information Society

• Oscillation (differential equation)
• Oscillation (mathematics)
• Oscillation (album), a studio album by the Norwegian gothic metal band Trail of Tears
• Oscillistor, a semiconductor device