Alexithymia involves difficulties in identifying, describing, and symbolically processing emotional states. Previous research has shown that childhood maltreatment is associated with alexithymia, but the psychological processes underlying this relationship remain only partially understood. The present study explores the mediating role of defence styles in the association between childhood maltreatment and alexithymia. The study was carried out on 402 Italian participants (M _age = 36.56, SD = 12.89, age range 19–78 years; 309 females), who completed the Childhood Trauma Questionnaire–Short Form, the Toronto Alexithymia Scale, and the Defence Style Questionnaire-40. Results indicated that childhood maltreatment was positively associated with the immature defence styles, which, in turn, was positively associated with alexithymia. The total indirect effect was significant, and the specific indirect effect through immature defence styles was significant. Conversely, mature and neurotic defence styles did not show significant indirect effects. The direct association between childhood maltreatment and alexithymia was not significant. The study provides evidence on the role of defence styles in alexithymia among individuals reporting childhood maltreatment. Limitations and future research directions are also discussed.