Six new marine species of the testate amoebid genus Paulinella are described using light and electron microscopic observations of material from Canada's Pacific Ocean coastal waters. In order of test (shell) size, from smallest to largest, the following new species are proposed: P. carsoni sp. nov., P. agassizi sp. nov., P. suzukii sp. nov., P. lauterborni sp. nov., P. multipora sp. nov. and P. gigantica sp. nov. Included in this survey are new observations on P. indentata Hannah, Rogerson & Anderson, from Canadian Pacific Ocean locations, but previously known only from Scottish coastal waters, and the common brackish/freshwater species P. chromatophora, from Ontario (Canada). These new discoveries more than double the number of previously known species of Paulinella, a genus significant for its role as a secondary producer in marine benthic ecosystems and for the possible role of its type species (P. chromatophora) as a model system for the endosymbiosis hypothesis of the evolution of chloroplast-bearing organisms.