Harper highlighted the funding for Toronto's transit system, which was outlined in April's federal budget, alongside Finance Minister Joe Oliver and Toronto Mayor John Tory today.
The trio made the announcement at the Toronto Transit Commission's Hillcrest Complex in midtown Toronto.
Oliver said the funding is all about making Toronto a liveable place for citizens and efficient place for job-creating businesses.
"We are an engine of the Canadian economy, the heart of the Canadian advantage," he said.
"If we can't get people moving in the GTA, our engine will splutter."
A grinning Tory said: "What a great day for the city of Toronto."
That budget included $750 million over two years, starting in 2017-18, and $1 billion for each year after, for a new public transit fund to help cities fight traffic congestion by encouraging public-private infrastructure projects.
Harper's announcement is taking place near Oliver's Eglinton-Lawrence riding. Harper also appeared with Oliver at an event in Toronto just two weeks ago.
Oliver's political future has been questioned of late, with rumours he may not run for re-election — although he has given no official indication he won't be a Conservative candidate again.
Former Conservative colleague-turned-Liberal MP Eve Adams is in a tough nomination fight in Eglinton-Lawrence and the hotly-contested Liberal nomination suggests a tough battle for the seat once the writ drops.