Monteith, who co-hosted the Teen Choice Awards in 2010, was found dead July 13 in Vancouver, British Columbia. An autopsy revealed the 31-year-old actor died of an overdose of heroin and alcohol.
He and Michele played an on-again, off-again couple in the popular Fox series "Glee" and dated off-screen for about a year.
Michele won Choice TV Actress in a comedy for her role on "Glee" and took the stage tearfully Sunday address the audience while wearing a necklace that said "Cory."
"I just wanted to be here today to personally thank all of you and tell everyone out there how much all of your love and support has meant to me over these very difficult past few weeks," she said.
She dedicated the award to Monteith saying, "For all of you out there who loved and admired Cory as much as I did, I promise that with your love we're gonna get through this together. He was very special to me and also to the world."
She went on to say that "we were very lucky to witness his incredible talent, his handsome smile and his beautiful, beautiful heart so whether you know him personally or just as (his 'Glee' character) Finn Hudson, Cory reached out and he became a part of all of our hearts."
"Glee" also won Choice TV Comedy and cast member Amber Reilly said, "Although we lost someone that we really love and that you guys love too, we are very fortunate to come back to a show where we feel the love of family and Cory was like a brother to us."
On the teal carpet prior to the show, another "Glee" star Naya Rivera, said it was therapeutic for the show's cast to be together since Monteith's death.
"It's really good for us to be able to be all together and be in the same room and celebrate people loving what we do."
There were also lighthearted, silly moments during the show, ripe for the screaming teens in the audience.
One Direction kicked off the night with their new song "Best Song Ever" while later in the show hosts Darren Criss and Lucy Hale got Harry Styles to twerk as the audience went wild.
Some of the show's celebrity presenters tried to use the opportunity as teaching moments for the younger audience.
"Tonight means your vote matters," said "Scandal" star Kerry Washington with "The Vampire Diaries" actor Ian Somerhalder, of the more than 150 million votes cast, setting a new record for the show.
Ashton Kutcher received the Ultimate Choice Award and after joking, "Let's be brutally honest. This is the old guy award," said he wanted to impart some life-lessons to his younger fans.
"The sexiest thing in the entire world is being really smart and being thoughtful and being generous," he said.
Actress Rebel Wilson used her time on stage winning the Choice Movie Actress Comedy award for "Pitch Perfect" to get vulgar. She made an off-color joke about One Direction's band name that was muted out by producers.
This year's telecast was from the Gibson Amphitheatre in Universal City, Calif.