"The truth is, my mother was very ill," Trudeau wrote. "She suffered a severe mental illness."
However, he wrote that that he grew up free of much of the emotional trauma that divorce can inflict on children.
Trudeau, the second youngest prime minister in Canada's history, now brings his own young family to Sussex Drive, the official residence of the prime minister in Ottawa where he spent much of his childhood. Married to former Quebec television host Sophie Gregoire, Trudeau has three children: Xavier, 8, Ella-Grace, 6, and one-year-old Hadrien.
Like his father before him, Trudeau is sometimes compared to another U.S. president who rose to power at a young age, Barack Obama.
"You want a government with a vision and an agenda for this country that is positive and ambitious and hopeful. Well, my friends, I promise you tonight that I will lead that government I will be that prime minister," Trudeau told supporters at a victory rally in Montreal, echoing Obama's campaign themes of hope and change.
Nelson Wiseman, a political science professor at the University of Toronto, said Trudeau generates the same excitement among his supporters that Obama did in 2008, along with big expectations that will be difficult to meet.
"There is no doubt about it, Justin is fabulous with people. He's a great people person," Wiseman said. "Barack Obama used to enter a room and it just changed."
And like Obama, he said, "There is a lot of hope invested in Justin."
This story corrects the date of a state dinner in Ottawa at which President Richard Nixon spoke to 1972 instead of 1974.