This book offers an integrated examination of the ecological and toxicological dimensions of pesticide effects on the diverse organisms that inhabit agricultural landscapes yet are not the intended targets of chemical applications. The book systematically builds from foundational concepts in agroecosystem ecology, exposure pathways, and the diversity of non-target species through the physiological, molecular, and population-level consequences of pesticide exposure, providing readers with both conceptual understanding and practical insight into one of the most pressing environmental challenges of modern agriculture. Throughout its chapters, the text navigates the complex interactions between chemical stressors and biological communities, addressing impacts on pollinators, soil biota and mycorrhizal associations, aquatic ecosystems, avian and mammalian wildlife, and the myriad invertebrates that provide essential ecosystem services such as biological control and nutrient cycling. Dedicated sections explore the molecular mechanisms of toxicity including oxidative stress, detoxification enzyme systems, and transcriptomic responses, alongside biomarker discovery through genomic and proteomic approaches, ecological risk assessment methodologies including predictive modeling of chemical drift, and the emerging role of artificial intelligence in ecotoxicological assessment. The book also examines sustainable alternatives including agroecological pest management systems and habitat manipulation strategies that reduce reliance on synthetic pesticides while maintaining agricultural productivity. Perspectives from ecotoxicology, molecular biology, ecology, and regulatory science, this work aspires to be both a foundational educational resource for students and researchers and a practical reference for professionals engaged in environmental protection, agricultural sustainability, and chemical risk assessment worldwide.