Accumulator may refer to:
- Accumulator (computing), in a CPU, a processor register for storing intermediate results
- Accumulator (energy), an apparatus for storing energy or power
- Capacitor, in electrical engineering, also known by the obsolete term accumulator
- Electrochemical cell, a cell that stores electrical energy, typically used in rechargeable batteries
- Hydraulic accumulator, an energy storage device using hydraulic fluid under pressure
- Accumulator (bet), a parlay bet