"We should really be investing in a waterfront for everybody and not simply for the people who fly," Miller told CBC Radio's Metro Morning on Thursday.
Miller's comments come after Porter president and CEO Bob Deluce unveiled a proposal at Billy Bishop Toronto City Airport on Wednesday to expand the runway, allowing for a new fleet of jets to land.
Miller said the waterfront is "in the midst of a tremendous revitalization" and "an expanded commercial airport, let alone one with jets, has no place in that."
"Toronto has this amazing opportunity with our waterfront," Miller said, adding that from what he's seen "the great cities of the world prize their waterfronts."
Miller ran and won the mayoralty in 2003 with a platform that included killing a planned bridge to the island airport.
The former mayor offered up Chicago as an example of a city similar its size and population to Toronto that famously closed its own downtown airport.
"Chicago's position is the waterfront is a place for people," said Miller. "That's a place where when decisions like this come they say no."
'This is going to create jobs'
Mayor Rob Ford did not comment on Wednesday, but others including his brother, Coun. Doug Ford, called the Porter plan the right move for the city.
"We are one of the few cities in North America where you can work and walk to the airport," Ford said.
"This is going to create jobs, going to create more tourists coming to the city," Ford said.
Coun. Adam Vaughan, whose downtown ward includes the island airport, warned that lifting the prohibition on jets would raise issues about noise and pollution.
"Those jets aren’t quiet, they aren’t clean," Vaughan said.
Coun. Karen Stintz also joined calls on Wednesday to reject the plan.
"I think the airport should operate within current guidelines — and that we shouldn't be thinking about having jets downtown on expanded runways," Stintz said.
The Toronto Port Authority said it wouldn't take any position on Porter's business plans.
"The TPA will not consider any change of use to the airport until a determination is first made by the elected representatives on Toronto City Council regarding Porter's proposed changes to the 1983 Tripartite Agreement," it said in a news release.
Any proposal to accommodate new, larger planes would mean extending the runway at the island airport.
The longest runway is currently just over 1,200 metres long. Porter is requesting it be expanded 168 metres at each end, bringing the total length to 1,552 metres.
Council would have to support extending the runways and lifting the current jet ban at the island airport, a decision likely to happen right before the 2014 election.
In the wake of Wednesday’s announcement from Porter, some at city hall were saying a big issue may now be emerging for the next city vote.
"There might be some left leaning mayoral candidates who would love to take this into the next municipal election and not talk about the real issues we face," Coun. Denzil Minnan-Wong said.