This review provides a comprehensive overview of transition metal oxides (TMOs) in catalysis, highlighting their diverse properties and applications. TMOs, due to their partially filled d orbitals and highly electronegative oxygen atoms, exhibit unique electronic structures that make them suitable for various catalytic processes, including electrocatalysis and photocatalysis. The review covers recent trends and challenges in the synthesis and characterization of highly functional TMOs, emphasizing mesoporous materials and their role in enhancing catalytic performance. It also discusses the use of ab-initio modeling for designing novel TMOs and their applications in various chemical reactions. The review further explores TMOs as photocatalysts and electrocatalysts, detailing their performance in water splitting, hydrogen evolution, and carbon dioxide reduction. Additionally, it examines TMOs in general catalytic applications, such as oxidations, selective reductions, and dehydrogenations. Finally, the review discusses the use of TMO-based ceramics in high-temperature applications, including Ceramic Matrix Composites (CMCs) and thermal/environmental barrier coatings (TBCs/EBCs) in the aerospace industry. The challenges in theoretical modeling of TMOs, particularly in understanding surface interactions and atomic-level processes, are also addressed.This review provides a comprehensive overview of transition metal oxides (TMOs) in catalysis, highlighting their diverse properties and applications. TMOs, due to their partially filled d orbitals and highly electronegative oxygen atoms, exhibit unique electronic structures that make them suitable for various catalytic processes, including electrocatalysis and photocatalysis. The review covers recent trends and challenges in the synthesis and characterization of highly functional TMOs, emphasizing mesoporous materials and their role in enhancing catalytic performance. It also discusses the use of ab-initio modeling for designing novel TMOs and their applications in various chemical reactions. The review further explores TMOs as photocatalysts and electrocatalysts, detailing their performance in water splitting, hydrogen evolution, and carbon dioxide reduction. Additionally, it examines TMOs in general catalytic applications, such as oxidations, selective reductions, and dehydrogenations. Finally, the review discusses the use of TMO-based ceramics in high-temperature applications, including Ceramic Matrix Composites (CMCs) and thermal/environmental barrier coatings (TBCs/EBCs) in the aerospace industry. The challenges in theoretical modeling of TMOs, particularly in understanding surface interactions and atomic-level processes, are also addressed.