Ford will include city, county and federal representatives, including Toronto Mayor John Tory, Ontario Transport Minister Caroline Mulroney and Federal Transport Minister Marco Mendicino.
Ford is expected to speak to reporters around 1 p.m.
The 16-kilometer, 15-stop subway line is expected to run from Exhibition Place, through the heart of the city center and finally to the Ontario Science Center.
Metrolinx says the project-related capital cost is $ 10.9 billion and the new transit line is expected to be operational by 2030.