<p>The widespread use of fluoroquinolone (FQ) antibiotics in both human and veterinary medicine has led to their identification as a new and persistent threat to aquatic ecosystems. Environmental hazards, public health concerns, and the spread of antibiotic resistance are all heightened by their impaired metabolism, inability to be treated by traditional wastewater treatment methods, and ongoing release. With an emphasis on the growing importance of lanthanum-based nanoparticles as sophisticated remediation agents, this review assesses the environmental occurrence, fate, toxicological effects, and removal methods of fluoroquinolones. This paper offers an in-depth investigation of the features, impacts on aquatic ecosystems, and remediation strategies of fluoroquinolones in environmental systems. This work concludes with a comparative, mechanistic evaluation of lanthanum-based nanomaterials for the removal of fluoroquinolones via adsorption and photocatalytic degradation. Their strong affinity, selectivity, structural adaptability, broad pH range, and reusability are rigorously assessed with respect to synthesis techniques and structure–performance correlations. Remaining problems, such as scalability, material stability, recovery, and possible environmental hazards, are also addressed. This analysis presents a cohesive approach connecting fluoroquinolone pollution with novel nanotechnological solutions. It offers recommendations for future material design and sustainable wastewater treatment strategies to reduce antibiotic contamination in aquatic ecosystems.</p>