Proposed are a vehicle seat monopost assembly and a vehicle seat mounted thereon. In one aspect, a drive part includes a housing mounted on a lower frame connected to a vehicle body and a first engagement part configured to be rotated by a drive source. A second engagement part suitably may include a thread configured to be engaged with the first engagement part and a cylindrical body configured to be fixed to a vehicle seat frame. A connecting sleeve part is seated on the drive part and has an inner space into which the lead screw part is fitted. The connecting sleeve part is configured to restrict a rotation in response to an operation of a rotation restricting member.