Antimicrobial resistance (AMR) constitutes a growing global threat, facilitated by the dissemination of antibiotic resistance genes (ARGs) through wastewater treatment plants (WWTPs). This systematic review, conducted following the PRISMA guidelines, compiles the risks associated with ARGs, as well as the factors that promote horizontal gene transfer (HGT) and the technologies applied for their removal. The literature shows that WWTPs act as reservoirs, where biological treatment conditions and the presence of sub-inhibitory contaminants (antibiotics, metals, and pharmaceuticals) accelerate HGT. Although conventional methods (chlorination, ozonation, UV) are effective at eliminating antibiotic-resistant bacteria (ARB), their ability to degrade persistent genetic material is insufficient. Therefore, advanced oxidation processes (AOPs) emerge as a key solution, with the photo-Fenton process standing out due to efficiently generating hydroxyl radicals, achieving the degradation of ARGs, an essential step to mitigate the spread of AMR into the environment.