This study aimed to design an agile marketing model in digital banking with a focus on sustainable development. In terms of purpose, the research is applied-fundamental, and methodologically, it adopts a qualitative approach based on Grounded Theory. The participant population comprised 14 academic and executive experts in agile marketing and digital banking, selected through purposeful sampling until theoretical saturation was achieved. Semi-structured interviews served as the data collection instrument, and research reliability was confirmed through the test-retest agreement index. Data were analyzed using the grounded theory methodology. The findings were identified within the paradigmatic model across six main dimensions: causal conditions (financial capacity, digital marketing capabilities, digital resources), contextual conditions (cultural capabilities, banking governance), intervening conditions (regulatory, technological, organizational barriers, and risk management), strategies (dynamic capabilities comprising decision-making agility, dynamic adaptation, digital innovation, and service outsourcing), and outcomes (sustainable development across economic, social, and environmental dimensions, alongside competitive advantage). The results indicate that agile marketing in digital banking represents a systematic strategy that, by integrating technology, data-driven approaches, and organizational agility, not only fosters a sustainable competitive advantage but also provides a robust foundation for sustainable development in the banking sector by reducing carbon footprints, expanding financial inclusion, and promoting corporate social responsibility.