What is the name of the first iPhone model to include a dual-lens camera?

The first iPhone model to include a dual-lens camera was the iPhone 7 Plus.

Apple introduced the iPhone 7 Plus in September 2016 alongside the standard iPhone 7. Its rear camera system combined two 12-megapixel cameras: a wide-angle lens and a telephoto lens. Together, they provided 2× optical zoom and formed the basis for Apple's early Portrait mode photography.

The telephoto camera gave the Plus model a major photographic advantage over the regular iPhone 7, which had only one rear lens. The iPhone 7 Plus could also use software and the two-camera system to create a depth-of-field effect that blurred backgrounds behind subjects.

The iPhone 6 Plus is sometimes confused with it because it introduced optical image stabilization to the iPhone line, but it had a single rear camera. The iPhone 8 Plus and iPhone X also used dual-camera systems, yet both arrived later, in 2017. Later iPhones expanded the idea with ultra-wide lenses, LiDAR, improved stabilization, and computational photography.