内存映射输入输出（英语：Memory-mapped I/O, MMIO，简称为内存映射IO），以及端口映射输入输出（port-mapped I/O, PMIO，也叫作独立输入输出（isolated I/O），是PC机在中央处理器（CPU）和外部设备之间执行输入输出操作的两种方法，这两种方法互为补充。除此之外，执行输入输出操作也可以使用专用输入输出处理器（dedicated I/O processors）——这通常是指大型电脑上的信道输入输出（Channel I/O），这些专用处理器执行自有的指令集。

Memory-mapped I/O (MMIO) and port-mapped I/O (PMIO) (which is also called isolated I/O) are two complementary methods of performing input/output (I/O) between the CPU and peripheral devices in a computer. An alternative approach is using dedicated I/O processors, commonly known as channels on mainframe computers, which execute their own instructions.