Semiconductor devices, FinFET devices and methods of forming the same are provided. In accordance with some embodiments, a semiconductor device includes a substrate, a first gate stack, a spacer, a first dielectric layer, a shielding layer and a connector. The first gate stack is over the substrate. The spacer is disposed on and contacted to at least one sidewall of the first gate stack. The first dielectric layer is aside the spacer. The shielding layer covers a top surface of the spacer and a top surface of the first dielectric layer. The connector contacts a portion of a top surface of the first gate stack.