iPadOS 15 is the third release of iPadOS, released on September 20, 2021. It settled the widget debt — widgets joined the home-screen grid anywhere, in a new extra-large iPad size, with the App Library arriving in the Dock — and rebuilt multitasking's discoverability: the three-dot menu atop every window made Split View and Slide Over visible controls instead of hidden gestures, added a windowing shelf, and enabled app "center windows."

Quick Note — a corner-swipe scratchpad that captures links and context from any app — debuted as the iPad's exclusive, and SharePlay, Focus modes, Live Text, and the rest of the iOS 15 generation shipped alongside.

Home-screen widgets and App Library; the multitasking menu, shelf, and keyboard shortcuts overhaul; Quick Note; Swift Playgrounds app building (build and ship App Store apps on iPad); Universal Control (delivered in 15.4 — one keyboard and mouse flowing across Mac and iPad); Focus, Live Text, SharePlay, and Safari's redesign shared with iOS 15.

Every iPadOS 14 device once again — iPad Air 2, iPad mini 4, iPad (5th gen), and all Pros onward — extending the tablet line's zero-drop streak to three releases.

iPadOS 15 closed the phone-parity gaps and made multitasking teachable, while Universal Control delivered the era's best ecosystem demo. Its modest scope drew "the iPad's hardware outruns its software" criticism — the M1 iPad Pro shipped months earlier — sharpening the pressure that produced iPadOS 16's Stage Manager.