The objective of this study was to understand how youth search for mental health information online. Youth partners were engaged at the onset of the project and provided input throughout on the design, conduct and analysis. Individual, semi-structured interviews with Canadian youth with experience searching for mental health information online were conducted. Data collection and reflexive thematic analysis proceeded concurrently. Fourteen youth were interviewed. Four main themes related to how youth search online emerged: mind-set shapes the search process; external factors shape the search process; key attributes of helpful information; and cues affecting trustworthiness of online information. Findings can inform the development of youth-friendly online mental health information that is perceived as helpful and trustworthy by youth. Ensuring youth have access to quality online mental health information, accessible to how they search for it, is critical to the mental health and development of youth.