An easily assembled swivel mount device includes a housing having a peripheral shoulder abutment and a peripheral ramp which extends toward the shoulder abutment and which terminates at a peripheral blocking protrusion, a swivel member swivelably mounted on the housing by means of a shaft, and a sleeve member having a leading abutment edge which is brought to abut against the shoulder abutment, and an inner peripheral guideway which extends away from the leading abutment edge and which terminates at a peripheral blocked ledge such that the blocked ledge can be retained behind the blocking protrusion after slipping over the peripheral ramp.