This paper describes a global professional development program called 21st Century Learning Design (21CLD), which helps teachers design academic lessons that integrate opportunities for students to develop 21st Century competencies in a variety of dimensions such as collaboration, knowledge construction, and the powerful use of ICT for learning. The framework and tools of 21CLD are grounded in learning science research, promoting aspects of these dimensions that have been shown to tie to deeper learning. The paper highlights the example of Crescent Girls' School in Singapore, which is implementing this program school-wide as a next step on its longstanding journey to leverage ICT for instructional innovation. Critical aspects of the school's supportive ecosystem include a clear and consistent vision for teaching and learning, strong teacher ownership and a common language of discourse, distributed leadership, and the use of ICT to support teacher professional development and lesson design. The paper describes results for teaching and learning through a Communicative Arts lesson that leverages place-based ICT tools for student knowledge construction. Although Crescent Girls' School is unusually well resourced and has a strong history of ICT use for learning, this case offers lessons that apply equally well for earlier-stage explorations into ICT.