When it came to online conversations this year, Canadians couldn't stop talking about politics, pop stars and sports -- OK, they couldn’t stop talking about one sports team in particular.

Prime Minister Justin Trudeau and pop star Justin Bieber were the two most mentioned Canadians on Twitter in 2015, according to Twitter Canada's Director of Media Partnerships Christopher Doyle.

Doyle said Trudeau experienced a meteoric rise on Twitter during the federal election.

"When the campaign started he actually had 681,000 Twitter followers," Doyle said. "He crossed the coveted one million mark in mid-November. He actually gained 40,000 Twitter followers on election day alone."

Coming in behind Trudeau was the other famous Canadian "Justin," pop star Justin Bieber.

The singer crossed the 70 million follower mark this year, a distinction only one other person (Katy Perry) shares, Doyle said.

This past year was a “turnaround” year for Bieber, who released his hit album "Purpose” in November, and starred in a racy Calvin Klein underwear campaign, Doyle said.

Also making the list of most mentioned Canadians in 2015 were singer Carly Rae Jepsen, Edmonton Oilers centre Connor McDavid and Blue Jays catcher Russell Martin.

In terms of hashtags, politics, mental health and the Toronto Blue Jays dominated the discussion.

The top five Canadian hashtags of the year were:

  1. #CDNpoli
  2. #BellLetsTalk
  3. #elxn42
  4. #BlueJays
  5. #ComeTogether

On Jan. 28, 4.7 million tweets were sent out with the hashtag #BellLetsTalk, in an effort to open up discussion about mental health issues, Doyle said.

Every year on Bell Let's Talk Day, Bell donates 5 cents for each tweet and social media share made using the hashtag #BellLetsTalk. Bell also makes a donation for each call and text made by Bell Canada and Bell Aliant customers.

This year, $6.1 million was raised for mental health initiatives, and #BellLetsTalk was a number one trend on Twitter in Canada and worldwide.

The Toronto Blue Jays' #ComeTogether rallying cry was also popular online this year, Doyle said.

Canadians were talking about the country's only MLB team this year, as they clinched the American League East in October, before losing to Kansas City in the ALCS. And during their dramatic 2015 run, the Jays gained more than 320,000 followers, Doyle said.

Meanwhile, Twitter continued to be an online platform for global conversations in 2015. This year’s top five global hashtags were:

  1. #ParisAttacks
  2. #BlackLivesMatter
  3. #MarriageEquality
  4. #RefugeesWelcome
  5. #IStandWithAhmed

Bieber made the list again, nabbing the spot of Canadian to be re-tweeted the most number of times. On Jan. 6, Bieber sent out a tweet to help launch launch his Calvin Klein underwear campaign. The black-and-white photo of Bieber wearing only his "Calvins,” along with the caption “It Begins” was retweeted more than 172,000 times.