Reclamation and marine infrastructure projects often adopted simple artificial vertical or sloping seawalls as coastal defences against wave action, flooding and land erosion. However, these structures do not possess any microhabitats that can be readily occupied and used by marine organisms as refuges and feeding grounds. Through incorporating the knowledge of marine ecology and collaboration with ecologists and architects, engineers now are able to design eco-friendly artificial structures to serve dual roles as coastal defences and functional ecosystems for enhancing marine biodiversity and ecosystem services such as carbon sequestration and biofiltration. In this presentation, I will introduce the basic ecological principles for eco-engineered shorelines and draw examples from different parts of the world. I will also highlight the results of several recent trials of eco-engineered shorelines in Hong Kong. The implementation of eco-engineered shorelines for restoring manmade habitats will support the national master plan of China for ecosystem restoration (2021-2035), and the United Nations Decade on Ecosystem Restoration (2021-2030).