The purpose of this paper is to explore sex-based differences in cardiovascular health (CVH) and the incidence of type 2 diabetes mellitus (T2DM) among women at different menopausal stages and men. A prospective cohort study was conducted, involving 126,818 participants without pre-existing T2DM from the UK Biobank. CVH was assessed using the Life's Essential 8. Absolute risks (ARs) and hazard ratios (HRs) were separately employed to assess the association between increased CVH and T2DM risk. The Accelerated Failure Time model assessed the impact of CVH on the time to T2DM onset. Over a mean follow-up of 168 months, 4,315 cases of T2DM were documented. In men, each one-point increase in CVH was associated with a 0.268% decrease in AR and a 6.4% decrease in HR for T2DM. In premenopausal, perimenopausal and postmenopausal women, each unit increase in CVH resulted in a 0.105%, 0.180% and 0.166% decrease in AR and a 7.7%, 5.2% and 6.4% decrease in HR of T2DM. The adjusted median time to T2DM onset was delayed by 12.46, 9.83, 11.5 and 21.43 months in the highest quintile of men, premenopausal, perimenopausal and postmenopausal women, respectively, compared with the lowest CVH quintile. As CVH improved, the reduction in AR for T2DM was more prominent in men than in women. HR trends for CVH and T2DM were similar in men and postmenopausal women. Increased CVH delayed the onset of T2MD in both men and women, with the most significant delay observed in postmenopausal women.