<p>Conformity to traditional masculinity ideologies (TMIs)&#xa0;has consistently been linked to increased psychopathology. However, little is known about the association with formal psychiatric diagnoses. Cross-sectional data from a randomized controlled trial were analyzed. A total of 317 men (mean age = 31.8, SD = 7.2) completed an online questionnaire assessing conformity to TMIs and underwent the Structured Clinical Interview for DSM-5 (SCID-5) in person. Participants had been pre-screened for depressive symptoms as part of the larger trial, resulting in a sample with an elevated prevalence of depressive symptoms. Inclusion criteria were male sex and gender, age between 25 and 50&#xa0;years, sufficient German-language skills, and no current or past psychopharmacological or psychological treatment. Overall, 200 participants (63.1%) met the criteria for at least one psychiatric diagnosis, in this pre-screened sample. Logistic regression analyses revealed that higher conformity to TMIs was associated with increased odds of receiving any psychiatric diagnosis (OR = 1.04, 95% CI [1.02, 1.05]), particularly depressive disorders (OR = 1.03, 95% CI [1.01, 1.04]) and substance-related and addictive disorders (OR = 1.03, 95% CI [1.01, 1.05]). No significant associations were found for attention-deficit/hyperactivity disorder or anxiety disorders. Exploratory analyses suggested a significant association between conformity to TMIs and personality disorders, and an initially significant association with sleep–wake disorders that did not survive correction for multiple testing. Higher conformity to TMIs is associated with an increased risk of fulfilling the criteria for a psychiatric diagnosis, especially depressive and substance-related disorders. As such, the study highlights the clinical relevance of including TMIs in the assessment and treatment of men suffering from mental disorders.</p><p><i>Trial registration</i>: ClinicalTrials.gov, Identifier: NCT05435222 (Registered: 27.06.2022)</p>