As part of a planned development for Billy Bishop Toronto City Airport, new land reclamation and related marine works are required to extend both ends of the main runway. Wave conditions at the eastern end of the runway are relatively mild, as the site is sheltered inside Toronto Harbour. However, the western runway extension will be directly exposed to strong winds, energetic wave conditions, high water levels, and winter ice conditions on Lake Ontario. An engineered revetment is required to prevent erosion, preserve stability, and protect the exposed western reclamation from attack by waves and ice. The design challenge was compounded by the requirement to minimize the frequency and extent of wave run-up and overtopping during storms to avoid frequent inundation of the runway. At the same time, the crest elevation of the perimeter revetment was limited by several requirements for safe operations at the airport. A large-scale 3D physical modelling study was crucial to develop, test, and optimize the design of the perimeter revetment and for costing the marine works. In order to accommodate the stringent design requirements, several innovative revetment design concepts (featuring lower crest elevations, milder slopes, thicker filter layers, and thicker armour layers than normally seen in conventional designs) were tested in a wide range of harsh wave, wind, and water level conditions. Once the development is approved, the longer runway will allow for expanded operations from Billy Bishop Airport, with the ability to reach destinations anywhere across North America. This will greatly benefit the citizens of Toronto and boost the local economy. The longer runway will also improve safety by reducing the risk of runway excursion.