Compatibility of Apple Watch Series 5 with iPhones The Apple Watch Series 5 is compatible with specific iPhone models. Below is a detailed breakdown of the requirements. iPhone Requirements iPhone Model iOS Version Required iPhone 6s iOS 13 or later iPhone 6s Plus iOS 13 or later iPhone 7 iOS 13 or later iPhone 7 Plus iOS 13 or later iPhone 8 iOS 13 or later iPhone 8 Plus iOS 13 or later iPhone X iOS 13 or later iPhone XR iOS 13 or later iPhone XS iOS 13 or later iPhone XS Max iOS 13 or later iPhone 11 iOS 13 or later iPhone 11 Pro iOS 13 or later iPhone 11 Pro Max iOS 13 or later iPhone SE (2nd gen) iOS 13 or later iPhone 12 and later iOS 13 or later