A connecting assembly is disposed between two opposite assembling sides of a first body and a second body of an electronic device. The connecting assembly includes an engaging member, an engaging portion and an elastic fixing mechanism. The engaging member is pivoted to the first body and the engaging portion is fixed to the second body. The elastic fixing mechanism is connected to the first body. When the first body is assembled to the second body, the engaging member rotates relative to the engaging portion from a first position to a second position, such that the engaging member is infixed to the engaging portion and the second body. Then elastic force of the elastic fixing mechanism fixes the engaging member together with the engaging portion and the second body, such that the first body is assembled to the second body. An electronic device having the connecting assembly is also provided.