The "Party For Two" singer recently recalled a dinner with the talk show host that she'll never forget, revealing things took a turn after a subject in particular came up.
"As soon as we started talking about religion, it all went sour," Shania said on the Sept. 28 episode of the Table Manners with Jessie and Lennie Ware podcast. "So it's like, 'Oh, let's stop talking about religion!'"
Claiming Oprah is "quite religious," Shania added that she is "not religious in the sense that I am dedicated to a religion. I'm much more of a spiritual person."
The "You're Still the One" singer added, "There was no room for debate and I like to debate."
Oprah has previously spoken about her strict Baptist upbringing but told AARP Bulletin in 2015 that while she still loves church, she doesn't identify as a "traditionalist" when it comes to religion. But while Shania remembers trying to deviate from the topic at dinner, she still looks back on meal fondly.
"She's such a smart lady," the 57-year-old noted of Oprah, "and it was just great to just sit and have real talks."
But Shania and Oprah are no stranger to one another. After all the "From This Moment On" singer starred in a 2011 reality series Why Not? with Shania Twain on the media mogul's network OWN.
Just days before the reality series launched, Shania did her first on-camera interview in over five years on The Oprah Winfrey Show, where she discussed the end of her 14-year marriage to Robert "Mutt" Lange over his alleged affair with her close friend and assistant Marie-Anne Thiébaud.
Following their split, Shania found a romance with Marie-Anne's ex-husband Frédéric Thiébaud.
"The person to comfort me was Fred because he's been through the exact same thing," Shania told Oprah in 2011. "Fred was safe."