A special broadcast in the Glenn Gould Studio in downtown Toronto marked the occasion, which host Matt Galloway told listeners was worthy of a special celebration.
"This is the 40th anniversary of this program and so we thought we'd throw a party and so to do that we've thrown our door open," he said.
Wednesday’s show was broadcast in front a live audience and followed by a special meet-and-greet with Metro Morning listeners.
The show first went to air on April 2, 1973, under the name Tomorrow is Here.
Forty years later, it has undergone many changes — including its name — and built a loyal audience among Torontonians who tune in each weekday morning to hear stories about their city and issues that matter.
"We are going to hear some of the folks who define this town and helped shape this town and talking about things that matter to people including our aging population, transit and how we’re going to pay for it and more," said Galloway.
Premier Kathleen Wynne was a guest on Wednesday's program, admitting that she has been listening to Metro Morning for many of the years that it has been in existence.
"I think this show is such an integral part of how we see ourselves and I've been listening for 36 years," she said.
The premier said there are many ways to map out one's life and she can think back to the many hosts she has listened to while waking up over the years.
The show received numerous shout-outs on Twitter from guests, fans and fellow broadcasters and journalists: