Background: Tobacco misuse has not been universally acknowledged as a modifiable risk factor in diabetes preventive or screening methods, despite mounting data revealing substantial epidemiological and mechanistic connections between smoking, hyperglycemia, and the development of type 2 diabetes. Purpose: A growing number of research on the effect of smoking cessation on the development of type 2 diabetes mellitus. The goal of this systematic review was to search the available evidence on the impact of smoking cessation and risk for type 2 diabetes mellitus. Methods: We searched PubMed, Embase, and Scopus (January 1995--October 2022) for prospective observational studies that evaluated the effects smoking and smoking cessation as risk factors for type 2 diabetes mellitus. Results: Type 2 diabetes risk was increased by a factor of 1.37 (95% CI: 1.33 to 1.42) for current smokers, 1.14 (1.10 to 1.18) for ex-smokers, and 1.22 (1.10 to 1.35) for passive smokers, compared to those who had never smoked (7 studies). The associations persisted across all subgroups, and a dose-response relation was discovered between current smoking and diabetes risk, with the RRs (95% CIs) for light, moderate, and heavy smokers, compared with never smokers, being 1.21 (1.10-1.33), 1.34 (1.27-1.41), and 1.57 (1.47-1.66), respectively. If there is a causal relationship between smoking and diabetes, we calculated that 10% in men and 2% in women of all instances of type 2 diabetes globally (about 25 million) may be attributed to smoking. The pooled RR (95% CI) from 10 studies showed that recent ex-smokers (within 5 years) had a lower risk of relapse than never smokers, while long-term ex-smokers (within 10 years) had a lower risk of relapse than current smokers. Conclusion: Both active and passive smoking are strongly connected with higher risks of type 2 diabetes. The risk of diabetes is higher among recent ex-smokers, although it lowers significantly with time.