Emerging contaminants (ECs) have become a growing environmental concern due to their continuous release into aquatic ecosystems through domestic wastewater, industrial effluents, healthcare facilities, and agricultural runoff. These contaminants, including pharmaceuticals, antibiotics, endocrine-disrupting compounds, personal care products, pesticides, industrial chemicals, and microplastics, are frequently detected in surface and groundwater at trace concentrations. Despite their low levels, many ECs are persistent, biologically active, and capable of bioaccumulation, posing significant risks to aquatic ecosystems and human health. This paper examines the occurrence, classification, and ecotoxicological impacts of emerging contaminants, emphasizing their adverse effects on aquatic organisms, such as endocrine disruption, reproductive abnormalities, oxidative stress, antimicrobial resistance, and biodiversity loss. It also highlights the role of physicochemical parameters, including pH, temperature, dissolved oxygen, biological oxygen demand, chemical oxygen demand, electrical conductivity, and total dissolved solids, in influencing the transport, persistence, and transformation of these contaminants in aquatic environments. Furthermore, the paper discusses advanced analytical techniques, including High-Performance Liquid Chromatography (HPLC), Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS), Gas Chromatography-Mass Spectrometry (GC-MS), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), for accurate detection and monitoring of ECs. The study underscores the need for effective monitoring, improved wastewater treatment, and sustainable management strategies to safeguard water quality, aquatic biodiversity, and public health.