USB On-The-Go通常缩写为USB OTG，是USB2.0规格的补充标准。它可使USB设备，例如播放器或手机，从USB周边设备变为USB主机，与其他USB设备连接通信。在正常情况下，这些支持OTG的USB设备和USB主机（如台式机或者手提电脑），仍然作为USB周边设备使用。

支持OTG的设备，如USB打印机，可以不连接电脑的情况下直接接入USB磁盘来读取磁盘内文档进行打印；或平板电脑可以直接接入USB磁盘、键盘或鼠标来扩充外界硬件功能。

USB On-The-Go, often abbreviated to USB OTG or just OTG, is a specification first used in late 2001 that allows USB devices, such as digital audio players or mobile phones, to act as a host, allowing other USB devices, such as USB flash drives, digital cameras, mice or keyboards, to be attached to them. Use of USB OTG allows those devices to switch back and forth between the roles of host and client. For instance, a mobile phone may read from removable media as the host device, but present itself as a USB Mass Storage Device when connected to a host computer.