Which macOS version introduced the Dark Mode feature?

macOS Mojave introduced the Dark Mode feature as a system-wide appearance option. Apple released macOS 10.14 Mojave on September 24, 2018.

Earlier Mac software had offered darker interface elements and individual applications could use dark themes, but Mojave expanded the idea into an operating-system setting. Its dark appearance changed the menu bar, Dock, controls, and supported built-in applications so that interface elements receded and content stood out. Developers could support the appearance through Apple’s public APIs.

Mojave was named after California’s Mojave Desert, continuing Apple’s series of California-inspired macOS names that began with OS X Mavericks. It also introduced Desktop Stacks, Dynamic Desktop wallpapers, and several iOS-derived apps. High Sierra preceded Mojave, while Catalina followed it; Big Sur and later releases came afterward, so none of those versions introduced the feature.