Android One users will get the update later this year, with the Sony Xperia XZ2 and XZ2 Compact, Xiaomi Mi Mix 2S, Nokia 7 Plus, Oppo R15 Pro, Vivo X21 and OnePlus 6 slated to receive the update some time in the autumn.
Android 9.0 went into beta in March, so there are few surprises left in store in terms of features.
The update brings with it a new iPhone X-a-like gesture-based navigation system and improved artificial intelligence features, including a new app called Adaptive Battery that prioritises battery power for users' most-used apps.
"Today we're officially introducing Android 9 Pie. We've built Android 9 to learn from you - and work better for you - the more you use it," gushed Sameer Samat, Google vice president of product management for Android and Google Play, in a blog posting introducing the update and revealing its underwhelming new name.
"Android 9 also helps you get things done faster with App Actions, which predicts what you'll want to do next based on your context and displays that action right on your phone," he continued.
"Say it's Tuesday morning and you're preparing for your commute: you'll be suggested actions like navigating to work on Google Maps or resuming an audiobook with Google Play Books. And when you put in headphones after work, you may see options to call your mom or start your favourite Spotify playlist."
However, some of Android Pie's headline features, such as Google's Digital Wellbeing dashboard that shows users information such as how many minutes they've spent on each app and how many times they've unlocked their smartphone, aren't yet available.
"Digital Wellbeing will officially launch on Pixel phones this fall, with Android One and other devices coming later this year," Google said, noting that these features are available in beta for Pixel phones running Android 9.0.
Slices, a feature that serves up relevant contextual information from your favourite apps, will also arrive later this year.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago