Abstract A randomized‐controlled‐trial study ( N = 219) tested two pre‐registered hypotheses that mobile‐phone app‐based mindfulness training improves wellbeing and increases self‐transcendent emotions: gratitude, self‐compassion, and awe. Latent change score modeling with a robust maximum likelihood estimator was used to test how those changes are associated in the training versus the waiting‐list group. The training increased wellbeing and all self‐transcendent emotions regardless of interindividual variance in the changes across time. Changes in all self‐transcendent emotions were positively associated with changes in wellbeing. The strength of those associations was comparable in the waiting‐list group and the training group. More studies are needed to test whether the effects of mindfulness practice on wellbeing are driven by increases in self‐transcendent emotions. The study was conducted over 6 weeks during the COVID19 pandemic. The results indicate that the mindfulness training can be an easily accessible effective intervention supporting eudaimonic wellbeing in face of adversity.