This paper investigates the relationships between optimism, mindfulness, and task engagement. Specifically, we hypothesized that optimism, mindfulness, and their interaction would facilitate individuals’ task engagement. We tested our research model in four studies: two surveys among gig workers and two experiments. The results of the two surveys among gig workers indicated that optimism predicted higher task engagement, but trait mindfulness did not, and that a multiplicative interaction existed between high optimism and high mindfulness in stimulating task engagement. Our two experiments confirmed a significant interaction between optimism and induced state mindfulness and showed that the most engaging situation is being high in both mindfulness and optimism. Although optimism predicted task engagement, the experiments indicated that the effect of the state mindfulness manipulation was above and beyond that of optimism. Finally, we discuss the nuances of the interaction between optimism and mindfulness in predicting task engagement.