Which came first, Android or Windows?

Windows came first, by 23 years. Microsoft shipped Windows 1.0.

Side by side

Android

Android as a company was founded in October 2003 — four years before the iPhone — originally to build an operating system for digital cameras. Google bought it in 2005 and the first Android phone shipped in October 2008, fifteen months after the iPhone went on sale. So Android is older than the iPhone as a project and younger as a product, which is why the question needs the distinction stated.

Windows

Windows 1.0 shipped in November 1985, twenty-two months after the Macintosh, and it was not an operating system — it was a graphical shell running on top of MS-DOS, and remained so until Windows NT in 1993 and the consumer transition with Windows XP in 2001. Version 1.0 could not even overlap windows: they tiled, because Apple's legal position on overlapping windows was unresolved.