Rachel McAdams learns of her 'Downton Abbey' roots on 'Who Do You Think You Are?'

Like many Canadians, Rachel McAdams was curious to learn more about her parents’ and great-grandparents’ heritage.

So the star set out to unearth her roots on an episode of TLC’s Who Do You Think You Are, a show that helps celebrities dig up details about their ancestry.

Rachel and her younger sister, Kayleen, trace back their genealogy on their mother’s side and discover that their great-great-grandfather was an English footman, similar to William Mason on Downton Abbey.

Being related to a footman is the last thing I was expecting,” Rachel says. “It's now this whole new world that we have a personal connection to.”

“But I still don't know how we got to Canada,” adds the 35-year-old actress, who was born in London, Ontario and now resides in Toronto.

Read more: Rachel McAdams' style transformation in photos

Next, the sisters head to Ottawa, where they are seen driving through the Canadian capital's downtown core. Both sisters agree, “It’s nice to be home,” as they pass by the parliament buildings.

While in Ontario, Rachel learns she has an important connection to Canadian history after discovering that another distant relative was a Revolutionary loyalist in the American colonies.

Watch a clip from the episode, which aired on Aug. 6, below.

Don't miss a beat with HELLO! Canada's Daily Hits newsletter, your daily dose of royal and celebrity news, fashion, weddings and more. CLICK HERE to sign up for free!