Metal oxide-based nanohybrids have become multipurpose materials that connect basic nanoscience with useful technology uses. They are appealing for a variety of sectors, from biology to energy and environmental remediation, due to their tunable physicochemical features and synergistic interactions. The main synthesis approaches—physical, chemical, and green/biological—are presented in a cohesive manner in this review, emphasizing their benefits, drawbacks, scalability, and appropriateness for various application requirements. Characterization methods including spectroscopy, diffraction, and microscopy are presented as crucial connections that link final functional performance with structure, composition, and morphology in addition to being analytical instruments.  Additionally, the review incorporates new advancements such as data-driven intelligent material design, sustainable synthesis utilizing microbes and plant extracts, and machine learning-assisted process optimization. All things considered, this work provides a coherent overview linking synthesis techniques, property assessment, and application potential, providing insights that can direct the future development of effective, environmentally friendly metal oxide nanohybrids designed for practical technological deployment.