Aims: Among employees with diabetes, comorbidity may considerably deteriorate working capacity. We examined how socioeconomic status, lifestyle factors and job strain were related to work disability in individuals with diabetes with and without comorbidity. Methods: In this pooled analysis of individual-participant data from occupational cohorts from Finland (Finnish Public Sector Study FPS), UK (Whitehall II) and France (GAZEL), 1925 employees with diabetes were followed on average for 4 years. Participants were categorized into four groups, according to their baseline comorbidity status and subsequent work disability, as: non-comorbid diabetes with no/low work disability; comorbid diabetes with no/low work disability; non-comorbid diabetes with moderate/high work disability; and comorbid diabetes with moderate/high work disability. The risk of work disability was assessed with multinomial regression, using Group 1 (the first listed above) as the reference group. Results: Participants with low socioeconomic status had increased odds for higher work disability, irrespective of comorbidity (OR = 3.12; 95% CI 2.25–4.33, among participants with no comorbidity, and OR = 2.61; 95% CI 1.93–3.51 among those with comorbidity). Obesity was cross-sectionally associated with comorbidity (OR = 1.95; 95% CI 1.35–2.83 for comorbidity without disability), and this association was particularly pronounced among those whom became work disabled (OR = 2.61; 95% CI 1.89–3.60 for comorbidity with disability). Job strain was associated with high/moderate work disability, only among participants with comorbidity (OR = 1.63; 95% CI 1.14–2.34). Conclusions: Pooled data from three cohort studies showed that low socioeconomic status, obesity, and job strain are linked to both comorbidity and increased work disability in employees with diabetes.