Wynne will make the announcement in Toronto on Monday morning and then fly to Quebec City to sign a memorandum of agreement with Quebec Premier Philippe Couillard around noon.
The announcement comes after Ontario has held public consultations on how to reduce its carbon emissions. Sources say Monday's announcement is timed to set the stage for the provincial and territorial leaders summit on climate change being held the next day in Quebec City.
The cap-and-trade system allows companies to either cap their greenhouse gas emissions or buy credits from companies that have reduced emissions.
Quebec implemented its cap-and-trade system in January 2015. As of February, the province has auctioned off $190 million worth of credits to reduce emissions.
Quebec operates its cap-and-trade system with California. Monday's announcement means that Ontario, Quebec and California could set up a joint system to allow companies to trade their emissions between all three jurisdictions, if Ontario signs a separate agreement with California.