The authors examine whether cognitive biases characterise youth depression, contribute to vulnerability, and play a causal role in the development and maintenance of depressive symptoms. The review finds relatively consistent evidence that attention and interpretation biases towards negative information are associated with youth depression and may represent cognitive vulnerability factors. Emerging findings from cognitive bias modification studies provide preliminary support for a causal role of these biases, although evidence remains limited and further research is needed in clinical samples. Overall, the review highlights cognitive biases as important mechanisms in youth depression and identifies promising directions for future prevention and intervention research.