Nicotinamide adenine dinucleotide (NAD⁺) is an essential metabolite that plays a crucial role in diverse biological processes, including energy metabolism, gene expression, DNA repair, and mitochondrial function. An aberrant NAD⁺ level mediates the development of cardiovascular dysfunction and diseases. Both in vivo and in vitro studies have demonstrated that nicotinamide mononucleotide (NMN), as a NAD⁺ precursor, alleviates the development of cardiovascular diseases such as heart failure, atherosclerosis, and myocardial ischemia/reperfusion injury. Importantly, NMN has suggested pharmacological activities mostly through its involvement in NAD⁺ biosynthesis. Several clinical studies have been conducted to investigate the efficacy and safety of NMN supplementation, indicating its potential role in cardiovascular protection without significant adverse effects. In this review, we systematically summarize the impact of NMN as a nutraceutical and potential therapeutic drug on cardiovascular diseases and emphasize the correlation between NMN supplementation and cardiovascular protection.