Background/Objectives: A favorable attitude towards suicidal behavior is associated with an increased risk of suicidal behavior in youth populations. Hence, the aim of the present study was to analyze attitudinal beliefs about suicidal behavior among Mexican medical and nursing students. We also compared attitudinal beliefs about suicidal behavior according to the religious affiliation of the participants. Methods: This is a cross-sectional observational study. Attitudinal beliefs about suicidal behavior were assessed using the Attitudinal Beliefs Questionnaire about Suicide Behavior (CCCS-18). We evaluated personal and family histories of suicide using the Spanish version of the MINI International Neuropsychiatric Interview. Comparative analysis between nursing and medical students was performed, using Chi-square tests for categorical variables and Student t-tests for continuous variables. Results: A total of 195 (52.2%) medical students and 178 (47.8%) nursing students participated. Medicine students reported a higher prevalence of a family history of suicide attempts and knowing someone who had tried to die by suicide compared to nursing students (p = 0.001). Regarding attitudinal beliefs—specifically, suicide in terminal patients—medical students reported higher scores than nursing students (9.50 ± 5.91 vs. 11.23 ± 6.38, p < 0.001), while the latter exhibited higher scores in attitudinal beliefs related to suicide itself (9.55 ± 4.45 vs. 7.28 ± 4.09, p < 0.001). Both groups display similar scores when compared by religious affiliation. Conclusions: Our findings show differences in attitudinal beliefs about suicidal behavior between medical and nursing students. Medical students exhibited more positive responses toward suicide in terminal patients, while nursing students had higher values for attitudinal beliefs related to suicide itself. These results could be considered in the planning of health sciences curricula in order to positively impact future suicide prevention efforts. This study was retrospectively registered at the Universidad Juarez Autónoma de Tabasco, with the registration number 20240063 on 8 June 2024.