The high penetration of renewable energy sources, particularly wind and solar power, creates operational challenges for active distribution networks due to their intermittent nature. This paper proposes a three-layer optimization framework for coordinated energy and flexibility management, in which microgrids provide flexibility services to the distribution network through distributed generation, energy storage systems, smart homes, and electric vehicles. In the first layer, smart homes optimize their energy consumption and flexibility participation. In the second layer, microgrids coordinate available flexible resources and determine their market participation. Finally, the distribution system operator optimizes the energy and flexibility markets based on the microgrids’ schedules. The proposed framework is formulated as a mixed-integer linear programming (MILP) problem and solved using CPLEX in GAMS. Simulation results demonstrate that the proposed approach can effectively meet network flexibility requirements, improve renewable energy utilization, and reduce the operating costs of both microgrids and the distribution network.