"'He just said it's 'David Johnson here,'" said Mercer in an interview Wednesday with CBC Radio's Metro Morning. "I'm not used to getting calls from the Governor General, so I thought it was [actor] C. David Johnson who played Chuck Tchobanian on Street Legal and was doing a show somewhere and decided to chat.
"I think I said, 'Thank you very much.' I'm humbled. I was so taken aback, it's not something I had anticipated. I just stumbled and said thank you. A lot. Over and over again."
Mercer is known for his wildly popular rants on his CBC show Rick Mercer Report. He was named to the Order for his charity work and "his ability to inspire and challenge Canadians through humour."
Many of political rants have become YouTube sensations.
"I'm very happy with the work that I get to do," said Mercer. "Travelling around the country and showing off the country to different parts of the country. The fact that something like this could happen was just a tremendous honour. I was deeply flattered. I was very moved."
Galloway also asked Mercer his take on Toronto Mayor Rob Ford, who returned to work this week after two months in rehab.
"I've kind of ignored Rob Ford," he said. "We never talked about Rob Ford much on the show because he was a municipal politician and you know, it's kind of like do the people in Toronto care what the mayor of Vancouver is up to and vice versa?
"But then overnight he became a global phenomenon and I personally didn't talk about him very much because I was embarrassed for my city. So I just avoided the subject honestly. I let the late-night comedians in the United States take care of that."