Question: can i update my apple watch series 1 to watchos 5?
Answer: Specifically, watchOS 5 does not support the original Apple Watch originally released in 2015. If you have an Apple Watch Series 1, Series 2 (both released in 2016), or Series 3 (2017), you'll be able to update your watch. ... Be aware that, in order to download watchOS 5, you'll need an iPhone running iOS 12.