This questionnaire-based study aimed to explore depression literacy (DL) and help-giving experiences in 12–18-year-old adolescents (N = 535, Mage = 14.9 years, 51.8% male) in Ireland. In response to a vignette depicting a character displaying symptoms of depression, 46.7% labelled these symptoms ‘depression’, with increasing age and empathy associated with increased likelihood of labelling as such. Almost all (92.1%) believed the character needed help, but the perceived helpfulness of potential responses varied. Over one-third (38.2%) indicated they knew someone who had displayed similar symptoms in the past year, with 85.2% of these reporting having helped this person. Reported help-giving responses included comforting the person, encouraging professional help-seeking, and informing an adult. The findings suggest adolescent DL can be best supported by developmentally-sensitive interventions that encourage empathy and the importance of engaging adults’ assistance.