Google Talk是Google公司于2005年8月24日推出的一款IP电话及即时通讯的服务。与其他即时通讯服务不同的是，Google Talk在使用开放的XMPP协议（原名Jabber），使用Google Talk服务不一定要通过官方客户端。VoIP使用XMPP扩展的Jingle协议。

Google Talk用户端仅支持Windows（2000、XP、Server 2003、7）和Google Chrome OS；在Android上被系统原生支持；对于其它的移动电话，支持BlackBerry、iPhone。XMPP协议的客户端软件列表列举了很多非Google提供的兼容软件。

Google Talk is an instant messaging service that provides both text and voice communication. The instant messaging service is colloquially known as "gtalk", or "gmessage" to its users, although Google does not endorse those names.

Google Talk was also the name of the client applications previously offered by Google to use the service. Google Talk applications were available for Microsoft Windows, Android, BlackBerry, and Chrome OS operating systems. A Google Talk mobile web app had also been previously available. In February 2015, the Windows client was discontinued and ceased to work, with Google recommending users to use Google Hangouts instead. Users of Windows client were instructed to migrate to the Google Hangouts app on the Chrome browser platform. It remained possible to connect to Google Talk with compatible third-party apps such as Pidgin and Gajim.