iPhone 6s and 6s Plus (2015) - First to introduce 3D Touch
  iPhone 7 and 7 Plus (2016)
  iPhone 8 and 8 Plus (2017)
  iPhone X (2017)
  iPhone XS and XS Max (2018) - Last models with 3D

Interesting that the iPhone SE 2nd/3rd generation with iPhone 8 form factor do not have 3D touch but "Haptic touch" instead.