Alkenes are fundamental components in synthetic chemistry, extensively used in the production of complex molecules for pharmaceuticals, materials science, and agrochemicals. Nickel-catalyzed transformations of alkenes via nickelacycle intermediates, formed by the oxidative cyclization of alkenes with other π-components on Ni(0), offer a promising approach characterized by high atom and step economy. Although numerous C–C bond formation reactions involving nickelacycles have been widely studied, there is a notable scarcity of comprehensive reviews that focus on transformations of alkenes. Recent progress in ligand design has enhanced control reactivity and selectivity, enabling a variety of nickel-catalyzed couplings. These include reactions of alkenes with carbon dioxide, isocyanates, alkynes, α,β-unsaturated carbonyls, aldehydes, ketones, and imines. This lack of in-depth discussion highlights the need for a detailed review that encompasses recent advancements in this field. This review summarizes these recent developments in nickel-catalyzed transformations of alkenes via nickelacycles, highlighting the advantages and challenges of this innovative strategy. The goal is to inspire new researchers to explore and contribute to this dynamic field, emphasizing nickelacycle intermediates as versatile tools for effective reactions with various π-components and identifying them as promising avenues for future research.