In computer hardware, a controller may refer to:

• Memory controller, a unit that manages access to memory

• Charge controller

• Game controller, a device by which the user controls the operation of the computer

• Host controller

• Sound controller

• Network controller

• Graphics controller or video display controller

• SCSI host bus adapter

• Parallel port controller

• Microcontroller unit (MCU)

• Keyboard controller

• Programmable interrupt controller

• Power management controller

• Northbridge (computing)

• Southbridge (computing)

• Universal asynchronous receiver/transmitter (UART) communications controller chip

• Peripheral DMA controller

• Disk controller

• Floppy disk controller

• Disk array controller, also known as a RAID controller, a type of storage controller

• Flash controller, or SSD controller, which manages flash memory

• Storage controller

• Terminal access controller

• IBM 2821 Control Unit, used to attach card readers, punches and line printers to IBM System/360 and IBM System/370 computers

• IBM 270x and IBM 37xx, used for telecommunications

• IBM 3271, 3272, 3271, and 3174, used to attach terminals (display devices)

• MIDI controller

• Programmable logic controller