Background: Smoking is a detrimental health behavior that can be addressed by designing stage-matched interventions with evidence-based behavioral change models such as the transtheoretical model (TTM). This study applied the TTM to predict smoking cessation stages among adults in Saudi Arabia. Methods: This social media-based cross-sectional study in Saudi Arabia used a convenient sample of 491 adult smokers (men and women). A digital questionnaire containing basic and smoking-related data and smoking scales (stages of change, cessation readiness, decisional balance, and self-efficacy) was used for data collection. The data were collected from 1 July to 30 October 2023 and were investigated using an ordinal regression analysis. The results illustrate that among the studied smokers, cigarette smoking was the prevalent method of smoking, especially among men (71.7%) compared to women (27.8%). Regarding stages of smoking, the pre-contemplation (35.8%) and contemplation (30.1%) stages were the highest, where men were more represented in both stages (37.9% and 40.8%, respectively). In comparison, women represented a higher percentage in the action (23.9%) and maintenance (21.1%) stages. The ordinal regression showed that increasing age (adjusted odds ratio; AOR = 1.045, p = 0.044), high quitting readiness (AOR = 1.134, p < 0.001), self-efficacy (AOR = 1.965, p = 0.028), decisional balance (AOR = 1.870, p < 0.001), and absence of psychological problems (AOR = 2.047, p < 0.001) increased the likelihood of being at higher smoking cessation stages. However, increased smoking duration (AOR = 0.756, p = 0.010), male gender (AOR = 0.340, p < 0.001), not working (AOR = 0.364, p = 0.013), adequate income (AOR = 0.535, p = 0.032), no chronic diseases (AOR = 0.430, p < 0.001), regular smoking (AOR = 0.052, p < 0.001), high smoking dependency (AOR = 0.775, p = 0.038), and hookah smoking (AOR = 0.032, p < 0.001) decreased the likelihood of being at higher smoking cessation stages. Conclusion: Cigarette smoking is a prevalent problem among Saudi adults, especially men, with the highest percentage of these being at lower smoking cessation stages. Thus, this study recommends the development of stage-matched interventions to facilitate the move towards higher smoking cessation stages through efforts by, and collaboration between, community sectors to face this rising issue.