Objective The study objective was to determine if disability in activities of daily living specific to prison, prison activities of daily living (PADLs), is associated with depression and severity of suicidal ideation (SI) in older prisoners, a rapidly growing population at high risk of suicide. Methods Cross‐sectional design using data from a study of prisoners age ≥50 years (N = 167). Depression was operationalized as a score of ≥15 on the 9‐item Physician Health Questionnaire (PHQ‐9). SI severity was assessed using the Geriatric Suicide Ideation Scale (GSIS). Participants were considered to have PADL disability if they reported any of the following as “very difficult” or “cannot do:” dropping to the floor for alarms, climbing on/off the top bunk, hearing orders, walking while wearing handcuffs, standing in line for medications, and walking to chow. Associations were examined with bivariate tests and with multivariable logistic and linear regression models, and the interaction term gender × PADL disability was tested. Results PADL disability was associated with depression and SI severity. There was no main effect of gender on either depression or SI, yet the association between PADL disability and depression was considerably stronger in male than in female older prisoners. Conclusions Identifying older prisoners who have difficulty performing PADLs may help distinguish prisoners who may also be likely to be depressed or experience more severe SI. Furthermore, the association between PADL disability and depression may be particularly salient in older male prisoners. Longitudinal studies are needed as causal inferences are limited by the cross‐sectional design. Copyright © 2016 John Wiley & Sons, Ltd.