ATAPI (ATA Packet Interface)是一款ATA协定，允许使用ATA连接到更多的周边设备，不仅限于连接硬盘。

ATA的设计原本只允许用来连接硬盘。小外形规格委员会 (Small Form Factor Committee)提出了ATAPI，增加了一些功能。例如光驱需要一个"media eject"指令来检查光盘是否已插入，这在原有的ATA协定并不提供。

ATAPI于1998年成为ATA协定的一部份，编号和名称为INCITS 317-1998, AT Attachment with Packet Interface Extension (ATA/ATAPI-4)。

ATA Packet Interface (ATAPI) is a protocol that has been applied to Parallel ATA and Serial ATA that allows a greater variety of devices to be connected to a computer than ATA would allow.

ATA was originally designed for, and worked only with hard disks and devices that could emulate them. The introduction of ATAPI (ATA Packet Interface) by a group called the Small Form Factor committee (SFF) allowed ATA to be used for a variety of other devices that require functions beyond those necessary for hard disks. For example, any removable media device needs a "media eject" command, and a way for the host to determine whether the media is present, and these were not provided in the ATA protocol.