Motivations for cannabis use may include coping with negative well-being. Life satisfaction, a hallmark of subjective well-being, could play a role in cannabis use among young adults. This study aims to assess whether life satisfaction (SWLS) at age 21 is associated with cannabis initiation and cessation between the ages of 21 and 25, and with cannabis use severity (CUDIT) at age 25. Data were drawn from a cohort of young Swiss males. Associations of life satisfaction with initiation, cessation, and severity were assessed with logistic and zero-truncated negative binomial regressions. Age, family income, education, alcohol, and tobacco use at age 21 were used as adjustment variables. From a sample of 4778 males, 1477 (30.9%) reported cannabis use at age 21, 456 (9.5%) initiated use between age 21 and 25, and 515 (10.8%) ceased by age 25. Mean (SD) SWLS was significantly higher among non-users at age 21: 27.22 (5.35) vs. 26.28 (5.80), p < 0.001. Negative associations between life satisfaction at age 21 and cannabis use initiation (OR = 0.98, p = 0.029) and severity at age 25 (IRR = 0.97, p < 0.001) were no more significant in adjusted analyses (OR = 0.98, p = 0.059 and IRR = 0.99, p = 0.090). Life satisfaction at age 21 was not associated with cannabis cessation (OR = 0.99, p = 0.296). Results suggest that the predictive value of life satisfaction in cannabis use is questionable and may be accounted for by other behaviors, such as tobacco and alcohol use.