This study assessed mental health literacy in Irish adolescents (N = 187), and explored participants’ help-giving responses toward hypothetical depressed peers. Participants read five vignettes, each describing an adolescent experiencing a life difficulty; two of the characters met Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV) criteria for depression. The majority of participants could not identify depression or potential suicidality, but felt concerned for the depressed characters’ well-being. Most participants stated they would provide help if they were the depressed characters’ friends. Correct identification of depression did not influence the type of help offered. A significant proportion of participants did not mention engaging an adult’s assistance, and assessing for suicidality was not mentioned by any participant. Gender differences were found in mental health literacy and the type of responses offered. Education that emphasizes the importance of informing an adult and assessing for suicidal risk is recommended.