During the coronavirus disease 2019 (COVID‐19) pandemic, mental health burden of university members sharply increased. Specific interventions to address pandemic‐related psychological distress did not yet exist. Current studies show that digital interventions reduce this burden, the investigation of changes in resilience as an outcome is lacking in these studies though. We therefore developed and evaluated the internet‐ and mobile‐based intervention “bounce” to foster resilience, reduce perceived stress, and psychological symptom burden among university members during the pandemic. The 8‐week, unguided internet‐ and mobile‐based intervention consists of one mandatory module promoting resilience and six optional modules on pandemic‐related topics. The study was designed as a one‐arm, longitudinal pilot study with a baseline and postintervention assessment and self‐reported resilience, perceived stress, and psychological symptom burden as outcome measures. The use and acceptance of the intervention modules were recorded and analyzed. A total of 798 individuals were given access to the intervention ( n = 70 employees, n = 728 students, M = 26.05 years, 71.8% women). Of these, 273 participants (34%) completed the postassessment. On average, participants logged on to the intervention platform four times and completed an average of 1.90 (SD = 1.64) modules. The intervention as a whole and all modules were well accepted by participants. Intention‐to‐treat analyses showed a significant increase in resilience ( t = −4.69, p < 0.001, d = 0.23) and a significant reduction in perceived stress ( t = 6.50, p < 0.001, d = 0.32), and psychological symptom burden ( t = 3.59, p < 0.001, d = 0.18) from baseline to postintervention. This study demonstrates that digital interventions can be easily developed and used as means to reduce mental health burden in large populations during a pandemic. The need for randomized controlled trials with follow‐up assessments to examine longer‐term effects and revisions of the intervention to increase effectiveness and use are discussed.