A chain master link tool includes a first lever and a second lever pivotally and releasably coupled together. Each of the first and second levers include a first working portions and a second working portion. The first and second levers are pivotal to an extended position in which the first working portions face oppositely and are disposed apart and cooperatively delimit a connection space therebetween for connection of a master link with a roller chain assembly and the second working portions face oppositely and are disposed apart and cooperatively delimit a removal space therebetween for removal of the master link from the roller chain assembly respectively.