She took the top honour Sunday night in Regina for her album, Kiss, the release she created last year after Justin Bieber brought her to the attention of his record label.
“There are so many people who deserve this. Thank you so much,” she said as she accepted the award from veteran singer Tom Cochrane.
Backstage, she said she expected Justin Bieber, who lost out to her in two of the categories, would be happy for her.
- Read a list of all the winners
"I think in general (it's) a shared success," said Jepsen, who said she hadn't heard from him yet but was "sure he'll send some love."
"The fact that he has really been my main supporter and he signed me, and because of that I was able to make the record Kiss and sort of be exposed to the world beyond Canada. So I have nothing to say to him other than thank you and I know he's been rooting for me just as much as his own stuff."
Bieber took the fan-voted Fan Choice Award and veteran singer Leonard Cohen was named artist of the year.
But the evening belonged to Jepsen, who stepped into the pop spotlight with her hit Call Me Maybe last year, declared "song of the summer" by Billboard magazine.
Call Me Maybe continues to be a sensation for the 27-year-old singer. She started off her Juno performance with the song before moving into other tunes from her album, Kiss, declared best pop album on Saturday.
Then she went on to win best single for Call Me Maybe.
- Photos: 10 key momentsat the Junos
"It’s crazy when you think one song can change your life, and it’s true, but it's also so, so many people.... The fans -- this is for you!" Jepsen said, before thanking a string of supporters, among them Bieber, who sealed her popularity when he promoted the video for Call Me Maybe to his legions of fans.
Bieber went into the Junos with four nominations, but lost in every category but Fan Choice. The Stratford, Ont., teen is on tour and was not present to accept his award.
Veteran singer Cohen was given the honours for songwriter of the year Sunday, with the award citing three songs from his latest album Old Ideas — Amen, Going Home and Show Me the Place. Cohen also was absent, but his son Adam Cohen accepted it on his behalf.
"I know he has a deep fondness for the love that Canada has always expressed toward him," Adam Cohen said. "He refers to Canada as the beating heart of his career."
On Saturday night, when the bulk of the prizes were handed out, Cohen scored another major prize — artist of the year.
Singer Michael Bublé hosted the Juno gala Sunday, opening the show with a skit that saw comedian Russell Peters, Dr. Phil and other personalities cast doubts on his ability to host the gala. He repeatedly made light of his slick image throughout the televised broadcast, but proved a genial host for an evening full of strong performances.
Serena Ryder started the evening's musical acts with her newest hit Stompa. Saskatoon's The Sheepdogs, Montreal's Metric, Billy Talent and David Myles and Classified also performed.
k.d. lang's heartfelt speech
But the highlight of the evening was k.d. lang's moving thank you to Canada after her induction into the Canadian Music Hall of Fame.
Anne Murray gave a fond look back at k.d. lang’s career – including when lang accepted her first Juno wearing a wedding gown – as she feted the Edmonton-born singer.
“I loved her sense of fun, her spunk, her gumption, and she could sing,” Murray said, recalling lang’s wild 1985 look. “She went on to show that a great voice could sing anything it wants. She defies labeling.”
Lang, whose 30-year career has ranged from country to pop to contemporary and back to country, accepted the honour wearing a black suit.
“Thank you so much for all your support over the years.I think the fact that I’m standing here receiving this award actually says more about Canada than it does about me,” she said.
- Photos: 12 red carpet moments
“Only in Canada could there be such a freak as k.d. lang receiving this award. Only in Canada could there be people like Stompin’ Tom Connors and Rita MacNeil. I want to tell you my friends and my countrymen that it is OK to be you. “
"It is OK to let your freak flags fly and embrace the quirkmeister that's inside of all of us. And I'm not even just talking artists, I'm talking every single person in this nation has the right to be themselves, live life... I love you Canada, thank you so much."
Backstage Lang revealed she'd spent a long time since learning she would be inducted meditating on what the honour meant.
“I just really think that Canada’s a special place. Not very many people would allow people like myself, Rita and Stompin' Tom to become national symbols,” she told CBC News.
Wins for Serena Ryder, Weeknd
Ryder took one of the evening's final Junos — best adult alternative release for Harmony, an album she said she wrote in a three-week burst of creativity before recording it in a studio at her Toronto home.
"It’s unreal. Unbelievable," she said backstage. "I'm so proud right now because I had the most fun making this record out of any record I’ve ever made. I just feel so proud and so excited."
The Weeknd — the stage name for 23-year-old Toronto native Abel Tesfaye — was a double winner at the non-televised event Saturday, winning both breakthrough artist of the year and R&B/soul recording of the year for his epic, ennui-steeped Trilogy. The album began life as three separately released free-to-download mixtapes yet still went gold in Canada and the U.S. upon its official commercial release.
The artist, known for shunning publicity, was not on hand to claim his award.
Hamilton, Ont.-based band Monster Truck were named breakthrough group of the year. The band, formed in 2009, are known for their single Seven Seas Blues.
The band made its name mainly through touring and live performances,
“Deep Purple was huge, we played with Deep Purple a year and a half ago and that’s pretty much as big as it gets, really,” said singer Jon Harvey in a backstage interview. The band has a new album, Furiosity, out May 28.
Vancouver pop-emo band Marianas Trench won the award for group of the year, triumphing in a field that included Rush, who were inducted into the Rock n' Roll Hall of Fame just last week.
Rush's Clockwork Angels did take the honours for best rock album Saturday night.
Montreal's Metric were also double winners, taking home the award for best alternative album for Synthetica and producer of the year for James Shaw.
"We’ve had some crazy times in the last year, including the release of Synthetica, played at Radio City Music Hall with Lou Reed, playing with best and oldest friends Stars," Shaw said. "Last year was special and we’re taking a little time to envision the future to see what’s next."
Also on HuffPost