Suicidal ideation and attempts are more prevalent during adolescence than at any other stage of life. Suicidal thoughts are the best predictors of a subsequent suicide attempt in children and adolescents. The purpose of this study was to identify latent classes or groups of youth with similar patterns of suicidal ideation using their responses to the five items of the Columbia-Suicide Severity Rating Scale, that measures suicidal ideation, plus a sixth item measuring intent to carry out suicide. This study included 388 adolescents admitted to primary and secondary mental health care programs in the Maule Region, Chile. Person-centered latent class analysis was utilized. Five classes were detected: ‘planners with intent’, ‘unintentional planners’, ‘non-planners with specific ideation’, ‘non-planners with nonspecific ideation’, and ‘non-ideators’. The class of ‘planners with intent’ was the most frequent (29.0%) and severe in all the indicators evaluated, comprising adolescents who reported self-injury, suicidal ideation, planning and at least one suicide attempt in their lifetime. The highest percentage of this class is represented by females (76.3%), middle adolescents (69.3%), living with both parents (43%) and presenting depressive disorder (57.9%). To enhance preventive strategies within healthcare services, it is recommended to include an assessment of the severity of suicidal ideation. This approach aims to mitigate risk factors that could potentially escalate to active suicidal ideation and suicide.