Which macOS version first included Siri?

macOS Sierra was the first macOS version to include Siri. Released as macOS 10.12 on September 20, 2016, Sierra brought Apple’s voice assistant to Mac computers for the first time after Siri had already become familiar on the iPhone, iPad, Apple Watch, and Apple TV.

Apple previewed the feature at WWDC in June 2016. On a Mac, Siri could answer questions, search the web, find files, send messages, create reminders, and control certain system functions. Its desktop design also added a results panel that could remain visible while users worked in another application.

The name itself is another source of confusion. Sierra was the first release to use the “macOS” branding instead of “OS X,” so it marked two transitions at once: the arrival of Siri on the Mac and a naming change that aligned the platform with iOS, watchOS, and tvOS. High Sierra and Mojave expanded and refined macOS, but neither introduced Siri to the platform.