Pathological retinal angiogenesis with irregular and fragile vessels (also termed as neovascularization, a response to hypoxia and dysmetabolism) is a leading cause of vision loss in all age groups driven in part by unmet metabolic demand from retinal neurons. Sustaining neural retinal metabolism with an adequate nutrient supply may prevent vision-threatening neovascularization. Low circulating serine levels are associated with neovascularization in macular telangiectasia and altered serine/glycine metabolism is suggested in retinopathy of prematurity. Here we assessed the role of serine metabolism in suppressing hypoxia-driven retinal neovascularization in mice. Systemic serine supplementation decreased, and dietary serine/glycine deficiency worsened retinal neovascularization. Fatty acid oxidation was essential in mediating serine protective effects and serine also increased the levels of phosphatidylcholine, the most abundant phospholipids in the retina. Exogenous serine increased abundance of proteins involved in oxidative phosphorylation in total retinas, as well as increased expression of mitochondrial respiration-related genes and decreased expression of pro-angiogenic genes in rod photoreceptor cluster. Pharmaceutical inhibition of mitochondrial energy production largely attenuated serine suppression of retinal neovascularization. Our data suggested that increasing serine is a potential therapeutic approach for neovascular eye diseases by enhancing retinal mitochondrial function and lipid metabolism to suppress driving factors for uncontrolled angiogenesis.