Sarcopenia is a skeletal muscle disorder. Recent studies have shown an association between muscle health and suicide. However, there have been no previous studies on the relationship between suicide risk severity and sarcopenia in major depressive disorder (MDD). This study aimed to explore the association between suicide risk severity and sarcopenia in non-elderly Chinese inpatients with MDD.The first-episode drug-naïve MDD inpatients aged 20-59 years with the 24-item Hamilton Rating Scale for Depression (HAMD-24) scores of >20 were included, who were then classified into low, intermediate, high and very high suicide risk groups according to the Nurses' Global Assessment of Suicide Risk (NGASR). The HAMD-24, the Hamilton Rating Scale for Anxiety (HAMA) and the SARC-F questionnaire were used to assess depression severity, anxiety severity and sarcopenia, respectively. The plasma levels of cortisol and adrenocorticotropic hormone (ACTH) were measured.A total of 192 MDD inpatients (122 females, 70 males; aged 39.3 ± 11.7 years) were included, with 12.5% meeting criteria for sarcopenia. There were significant differences in gender, HAMD score and prevalence of sarcopenia among the suicide risk groups. Adjusted ordinal regression analysis showed that sarcopenia was significantly associated with more severe suicide risk (OR = 2.39, 95%CI 1.02-5.58, p = 0.044) independent of depression severity.This study revealed that sarcopenia was significantly associated with higher suicide risk in non-elderly Chinese MDD inpatients after adjustment for depression severity. Intervention of sarcopenia might be effective in reducing the risk of suicide in non-elderly MDD patients.