This review discusses the role of nickel (Ni) in electrochemical organic oxidation reactions (OORs), highlighting its importance in the sustainable and efficient oxidation of various organic compounds. Ni-based catalysts are crucial for OORs due to their unique redox activity and chemical stability. The review explores how strategic choices, such as the use of foreign metals, intercalating species, and defects, can tune the electrochemical performance of Ni-based catalysts. It also examines the active species in different reaction environments and reaction mechanisms, including phase changes in the catalyst. The review emphasizes the limitations of current approaches and potential future advancements in OORs. The review begins by discussing the importance of OORs as an alternative to the oxygen evolution reaction (OER) in water electrolysis, which is energy-intensive and inefficient. OORs offer a more sustainable and efficient method for producing hydrogen and other valuable chemicals. The review then delves into the mechanisms of organic oxidation, including the oxidation of alcohols, amines, aldehydes, hydroxymethylfurfural (HMF), and urea. It discusses the impact of reactant hydrophilicity on OORs, highlighting the role of mass transport, surface interactions, interface electrochemistry, reaction kinetics, and desorption dynamics. The review also examines the dynamic behavior of Ni valence states during OORs, emphasizing the importance of understanding the oxidation state and redox behavior of Ni in optimizing OOR performance. It discusses the electrochemical redox behavior of Ni in the absence and presence of organic substrates, the determination of oxidation states using techniques such as XANES, XPS, and Raman spectroscopy, and the role of secondary elements in modulating the oxidation state and electronic structure of Ni. The review highlights the importance of phase changes in Ni-based catalysts during OORs, as these changes significantly affect the selectivity and efficiency of product formation. It discusses the effect of phase changes on the catalyst's activity and the role of different elements in enhancing the performance of Ni-based catalysts. The review concludes by emphasizing the need for further research into the active catalyst phase during long-term OORs and the potential for future advancements in this area.This review discusses the role of nickel (Ni) in electrochemical organic oxidation reactions (OORs), highlighting its importance in the sustainable and efficient oxidation of various organic compounds. Ni-based catalysts are crucial for OORs due to their unique redox activity and chemical stability. The review explores how strategic choices, such as the use of foreign metals, intercalating species, and defects, can tune the electrochemical performance of Ni-based catalysts. It also examines the active species in different reaction environments and reaction mechanisms, including phase changes in the catalyst. The review emphasizes the limitations of current approaches and potential future advancements in OORs. The review begins by discussing the importance of OORs as an alternative to the oxygen evolution reaction (OER) in water electrolysis, which is energy-intensive and inefficient. OORs offer a more sustainable and efficient method for producing hydrogen and other valuable chemicals. The review then delves into the mechanisms of organic oxidation, including the oxidation of alcohols, amines, aldehydes, hydroxymethylfurfural (HMF), and urea. It discusses the impact of reactant hydrophilicity on OORs, highlighting the role of mass transport, surface interactions, interface electrochemistry, reaction kinetics, and desorption dynamics. The review also examines the dynamic behavior of Ni valence states during OORs, emphasizing the importance of understanding the oxidation state and redox behavior of Ni in optimizing OOR performance. It discusses the electrochemical redox behavior of Ni in the absence and presence of organic substrates, the determination of oxidation states using techniques such as XANES, XPS, and Raman spectroscopy, and the role of secondary elements in modulating the oxidation state and electronic structure of Ni. The review highlights the importance of phase changes in Ni-based catalysts during OORs, as these changes significantly affect the selectivity and efficiency of product formation. It discusses the effect of phase changes on the catalyst's activity and the role of different elements in enhancing the performance of Ni-based catalysts. The review concludes by emphasizing the need for further research into the active catalyst phase during long-term OORs and the potential for future advancements in this area.