Leadless power amplifier (PA) packages and methods for fabricating leadless PA packages having topside terminations are disclosed. In embodiments, the method includes providing electrically-conductive pillar supports and a base flange. At least a first radio frequency (RF) power die is attached to a die mount surface of the base flange and electrically interconnected with the pillar supports. Pillar contacts are further provided, with the pillar contacts electrically coupled to the pillar supports and projecting therefrom in a package height direction. The first RF power die is enclosed in a package body, which at least partially defines a package topside surface opposite a lower surface of the base flange. Topside input/out terminals are formed, which are accessible from the package topside surface and which are electrically interconnected with the first RF power die through the pillar contacts and the pillar supports.