Previous research has shown marital status and marital quality are consistent predictors of health outcomes, including cardiovascular disease and mortality. To better understand the relationship among marital status, marital quality, and cardiovascular health, we examined how marital status and marital quality were associated with an early indicator of deteriorating cardiovascular health, high-frequency heart rate variability (HF-HRV). This study uses data from the National Survey of Midlife in the United States (MIDUS) Biomarker Substudy (N = 907) to examine differences in HF-HRV by traditional marital status categories (married, divorced, widowed, and never married) as well as further differentiating between the continuously married and remarried. In addition, links were also examined between HF-HRV and changes in marital quality (marital satisfaction, support, strain) among individuals in long-term marriages. No significant differences in HF-HRV were observed between married persons and those widowed, divorced, and never married. However, continuously married individuals had higher HF-HRV than remarried adults. Increases in marital satisfaction and support over 10 years were associated with higher HF-HRV, whereas increased marital strain over 10 years was associated with lower HF-HRV. Higher HF-HRV among the continuously married compared with the remarried suggests that previous marital disruptions may have lasting effects on cardiovascular health or that there may be other differences between the remarried versus those who remain married to the same person. Associations between marital quality and HF-HRV suggest that variations in the quality of one’s marriage may affect cardiovascular health.