Objective A number of studies have revealed that the number of completed suicides decreases with increasing body mass index (BMI). However, only few studies have evaluated the association between suicidal behavior, suicide attempts, and the various BMI categories. The aim of this study was to determine whether obesity is positively associated with increased suicide attempts and suicidal behavior with consideration of gender differences. Methods In a representative German population‐based sample (N = 2436), interviews were conducted in 2011 to examine the prevalence of suicide attempts and suicidal behavior in participants in the different BMI categories. Logistic regression analyses were conducted for suicidal behavior and suicide attempts to examine the association between obesity status and suicidality, controlling for confounding variables. Suicidal behavior was assessed by the Suicidal Behaviors Questionnaire‐Revised (SBQ‐R), which is a four‐item self‐report measure of suicidal thoughts and past attempts. BMI was calculated from participants’ self‐reported height and weight. Results Analyses revealed that extremely obese participants (BMI ≥ 40.0) had a prevalence rate of suicidal behavior of 33% for female respondents and 13% for male respondents and rates for suicide attempts of 27% for female and 13% for male respondents. No significant gender differences could be found for any of the weight categories. Furthermore, adjusted odd ratios (AOR) showed a significant difference in suicidal behavior in class I obesity (OR, 3.02 [1.50–6.08] and class III obesity (OR, 21.22 [6.51–69.20]. AORs for suicide attempts showed significantly greater odds for class I obesity (OR, 3.49 [1.76–6.90] and class III obesity (OR, 12.43 [3.87–39.86] compared to the normal weight group. Conclusion These results support a positive relationship between suicidal behavior, suicide attempts, and obesity. However contrary to previous findings, no gender differences were found. The findings support the introduction of routine screening for suicidal behavior in extreme obese individuals.