Biases in processing ambiguous emotional stimuli are thought to precede, and confer risk for, clinical depression. It has long been theorized that those who appraise ambiguous stimuli more negatively experience greater negative and less positive emotion in their day-to-day life, which in turn relates to symptoms of depression. To test this theory, we assessed links between a negativity bias task, ecological momentary assessments of emotion, and self-reported symptoms of depression in 154 young adults. Here, negativity bias was operationalized as the degree to which ambiguous emotional faces were rated negatively. We found that greater negativity bias in the laboratory predicted greater daily mean negative affect and lower positive affect across the semester. Critically, we also found that mean daily affect linked negativity bias with symptoms of depression. These results highlight how individual differences in information processing may be connected to real-world emotional profiles and risk for psychopathology.