Cancer and atherosclerotic cardiovascular disease (ASCVD) represent two of the leading causes of death worldwide. Increasingly, these two are being recognized as biologically related conditions rather than entirely segregated disease states. In addition to traditional risk factors such as aging, smoking, and obesity, chronic inflammation may be a key factor connecting the two illnesses. Endothelial dysfunction, oxidative stress, plaque progression, and thrombosis are all facilitated by inflammatory signaling in ASCVD. Similar pathways are known to contribute to cancer growth and invasion. Emerging epidemiologic data demonstrate increased cancer incidence among patients with cardiovascular disease, while cancer survivors and recipients of cardiotoxic therapies exhibit accelerated vascular disease. This narrative review aims to describe the bidirectional relationship between ASCVD and cancer. Targeting shared pathways using statins, colchicine, canakinumab, IL-6 inhibition, and lifestyle modification may provide dual benefits. Future biomarker-guided trials with integrated cardiovascular and oncologic endpoints are needed to clarify causality and optimize prevention and management.