Taoiseach Leo Varadkar, Ireland's first gay PM, attended Sunday's event with his Canadian counterpart Justin Trudeau.
The leaders also held talks, where they discussed a range of issues, including Brexit and abortion.
Mr Varadkar and Mr Trudeau met for the first time when the Canadian prime minister visited Ireland in July.
Mr Trudeau said the taoiseach was the first foreign leader to take part in a pride event in Canada.
Speaking at a joint news conference after the bilateral talks, Mr Varadkar said he discussed the issue of abortion with Mr Trudeau. He stated that he wanted to hold a referendum on the Eighth Amendment in the first half of next year.
The Eighth Amendment to the Irish constitution was passed in 1983 and granted a foetus equal right to life as its mother, effectively outlawing abortion.

The scheme will see the town hall converted to house "nationally significant" collections.
Kirkcudbright Common Good Fund agreed to support the project with a total of £130,000.
The money will allow the creation of a second floor gallery to host a hoard of Viking treasure found in the region.

The plane was salvaged from the bottom of Loch Doon in Ayrshire in 1982 after a four-year search by divers.
It crashed during a training flight from Ayr in 1941, killing the Czech pilot.
Returning the bodywork to its former glory has taken 35 years of work and involved several false starts before being carried out.
However, the Spitfire is finally ready to take pride of place at Dumfries and Galloway Aviation Museum whose founders first commissioned the salvage project way back in 1977.
Chairman David Reid said it was a fantastic addition to their collection.
"When we first started, most of the bits and pieces we were recovering then were coming from wartime crash sites and this one looked a peach," he explained.
"We contacted the local diving club in 1977, just after the museum opened in the July, and they agreed to take on the task of looking for this.
"We were expecting them to find it the first weekend - they found a syrup tin."
However, the search continued for four years with "countless hours of diving".
"They finally found it in 1982, probably just by feel, because the silt at the bottom of Loch Doon is several feet deep," said Mr Reid.
"They actually bumped into to it, I think the engine was the first part they found."
That was just the start of another long journey towards its restoration.
A Yorkshire-based expert was able to finish the fuselage but could not work on the wings due to ill health.
Eventually the museum secured some funding to buy a set of wings and the plane has finally been able to go on show.
"If you ask anybody in the UK or probably worldwide to name the most famous World War II aircraft - depending on which side you were on, it is almost certainly going to be a Spitfire," said Mr Reid.
"It was the greatest World War II fighter, really."
Although the exterior of the plane has been largely completed there is still a significant amount of work to do to the interior.
Nonetheless, the museum is optimistic that it can be carried out in the not too distant future.
"Hopefully within the next couple of years we will be able to let people actually sit in a genuine Battle of Britain survivor," said Mr Reid.
Irish Prime Minister Leo Varadkar began his three-day visit to Canada by taking part in the Montreal Pride Parade.
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An additional slice of funding has been agreed in order to allow £3.1m plans for a major art gallery in Kirkcudbright to proceed.
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A restored World War II Spitfire that saw service in the Battle of Britain has gone on public show in Dumfries.