Apple Watch Series 3 and Magic Keyboard
Is it at all possible to use an Apple Magic Keyboard with Apple Watch Series 3?
iPhone X, iOS 11.4, Apple Watch Series 3
No. I don’t know why you would even try such a thing. If you need to type long messages or emails just switch to your phone. You can only connect Bluetooth headphones, earbuds, medical devices, and gym equipment to your Apple Watch.