"René, this one's for you," she said through tears at the conclusion of her heartfelt acceptance speech. "The show must go on."
Dion, 48, expected to receive the award from Seal, but was shocked when the British singer called her son René-Charles on to the stage to present her with the award.
"I'm sorry for crying," she said as she gripped her 15-year-old son's hand. "I want to be so strong in front of my family and my kids."
Later, she thanked her fans and those close to her for supporting her extraordinary career.
"Music has been my passion since almost I can remember," she said. "So many people helped me get where I am today ... most especially I want to thank the fans for traveling through music with me in good and bad times."
She also thanked her three children, and then poignantly thanked her late husband.
"Most importantly, my beloved husband who I know will continue to watch over me from up above," she said.
Just before the speech, Dion performed a stunning rendition of Queen's classic 1991 song, "The Show Must Go On."
The star was joined on stage by electronic violin sensation Lindsey Stirling, who is the highest-paid woman on YouTube with more than 7.8 million subscribers and 1 billion channel views.
Of the song selection, Mark Bracco told WHO ahead of the show, "it is an amazing choice."
"Céline Dion has a huge repertoire of monster hits and she personally chose to perform 'The Show Must Go On' as her Icon performance on the Billboard Music Awards. I think at this moment in her life, the song has many meanings," he said.
The Icon Award celebrates a lifetime of achievement in the music industry, and has only been given to four other artists, including Jennifer Lopez and Prince.