The province will now work with Ottawa to iron out details of how the job training program will work, said Brad Duguid, minister of training, colleges and universities.
"This now opens the door to us working with the federal government to ensure we're providing the best possible programs we can for out-of-work Ontarians and, ultimately, out-of-work Canadians," he told The Canadian Press in an interview.
"It's an example of the provincial and territorial governments standing up for our vulnerable workers and, at the same time, getting to a point where both governments are working together."
The provinces and territories had refused to sign on to the original proposal that was the centrepiece of the 2013 federal budget, aimed at giving employers more input on job training programs.
The plan was to provide $15,000 for each eligible worker, with the cost divided equally between Ottawa, the provinces and employers.
The provinces and territories balked, saying Ottawa would claw back federal dollars for successful job-training programs run by the provinces, while forcing them to find millions more to cover their portion of the grant.
But they dropped their opposition last week after Ottawa agreed to a number of changes, including covering the provincial portion of the grant.
Both sides have come a long way over the past year, said Nick Koolsbergen, a spokesman for federal Employment Minister Jason Kenney.
Ontario, which was one of the most vocal opponents of the original proposal, is the first province to sign on, he said.
"I think it's a sign of how far things have come," he added.
Duguid said he expects the other provinces and territories will soon sign on to the framework agreement.
Ontario has also had good discussions with Ottawa over two other labour agreements for older and disabled workers that will expire soon, he said.
Quebec refused to sign on to the Canada Job Grant, but finalized a deal with the federal government earlier this week to renew a labour market agreement which includes many of the same elements.
Unlike other provinces, Quebec has a dedicated training fund that gives employers a say in how the money is spent, said Koolsbergen.
Ottawa will be getting better reporting from Quebec about where the money is going to ensure that employers remain at the centre of the training system, he said.
"We've acknowledged that the Quebec system already has employer investment and employer involvement in training," he said.
"So we've agreed to renew the pre-existing labour market agreement with Quebec because they're already doing what we're trying to accomplish with the rest of Canada with the Canada Job Grant."