Split early childhood education and childcare systems (ECEC) have historically been a common phenomenon, but today many countries are moving towards more coherent approaches to ECEC. Canada, however, has continued to maintain a divided ECEC situation. Reviewing Canada’s ECEC in 2004, the OECD suggested that greater integration of kindergarten and childcare would bring real advantages. In 2007, Ontario, Canada’s largest province, began to develop integrated “full-day early learning” for all four and five year olds. In the initial phase, several key challenges have emerged: first, merging the public kindergarten system with market-driven childcare; second, financing the new program; third, maintaining stability in user-pay childcare as four and five year olds move to the new program; fourth, determining staffing models, bridging differences between kindergarten and childcare staff; and fifth, managing the phase-in. How Ontario meets these challenges will have major implications for the future of ECEC programs across Canada.