A mounted child bicycle seat assembly for providing a selectively attachable auxiliary seat for a conventional bicycle that is in front of the base bicycle seat. The mounted child bicycle seat assembly includes an attachable seat having a seat portion for receiving the rear of a passenger and an attachment pole that attaches to a clamp assembly, defined by a upper clamp section, a lower clamp section and two clamp screws, connected to a bracket assembly that is defined by two mirror image elongated bracket members, each having a foot peg extending therefrom. The mounted child bicycle seat assembly attaches to the top tube of the frame of a conventional bicycle, in front of its base bicycle seat, thereby enabling a smaller passenger, such as a child to ride in front of the rider on the base bicycle seat on the attachable seat.