Abstract: Per- and polyfluoroalkyl substances (PFASs) are compounds in which one or more hydrogen atoms in the carbon chain are partially or completely replaced by fluorine atoms. A large number of studies have shown that aquatic environments seriously contaminated by PFASs can cause developmental toxicity, neurotoxicity, reproductive toxicity, and endocrine disruption to aquatic organisms. At present, the United States, Australia, Canada, and the European Union, among other countries/organizations, have issued freshwater aquatic life criteria for two traditional PFASs: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). To gain an in-depth understanding of the research status and challenges of establishing PFAS freshwater aquatic life criteria, this study systematically summarized the criteria values of PFOA and PFOS in different countries/organizations and compared their differences in species selection, data sources, and criteria derivation methods. There are significant differences, ranging from 2 to 6 orders of magnitude, in criteria for PFOA and PFOS in different countries/organizations. This may be caused by the following reasons: (1) Different countries/organizations have selected different test species, covering different taxa. (2) The toxic effects of PFASs are diverse, but there are fewer standardized experimental designs, resulting in significant differences in the results of different studies, and different countries/organizations have different standards for whether to use certain experimental toxicity data. (3) There is a high degree of uncertainty in chronic toxicity data inferred from the acute to chronic ratio. (4) Different countries/organizations use different methods to derive PFAS criteria for freshwater aquatic organisms. Therefore, the formulation of PFAS criteria for freshwater aquatic organisms still faces many challenges, such as the single controlled substance, insufficient basic toxicity data, unclear bioaccumulation effects, complex effects of mixtures, and the selection of criteria derivation methods. To better protect aquatic ecosystems, it is necessary to gain a deeper understanding of the environmental behavior, toxic effects, and bioaccumulation characteristics of PFASs through interdisciplinary collaboration, global data sharing, and toxicity prediction to support the scientific development of more water quality criteria for PFASs.