The PM first met Queen Elizabeth II when he was a kid before meeting her as prime minister in 2015.
During a special sitting of the House of Commons in honour of the queen's life on September 15, the prime minister delivered remarks to pay tribute to Queen Elizabeth following her death.
"When someone lives until 96, this should not have come as a surprise, and yet her sudden absence has struck us all palpably and profoundly," Trudeau said.
He noted that the queen "exuded a humility and compassion" that was a comfort to everyone.
"I was extraordinarily fortunate to have known Her Majesty throughout my life," he continued.
Then, the prime minister shared personal details about his relationship with Queen Elizabeth, including the first time he met her as a child and when he met her as Canada's leader.
"The first time I met her was in 1977 when I was just a little boy," Trudeau said. "When I would meet with her as prime minister almost four decades later in 2015, I joked that the last times we had met, she had been taller than me."
Not to be outdone, the queen responded with a joke of her own. She quipped that Trudeau was making her feel old!
"Her sense of humour was one of her many great qualities and one of the many reasons why she was one of my favourite people in the world," the prime minister said.
Trudeau also mentioned that his conversations with Queen Elizabeth were "candid," and they discussed "anything and everything" together.
"She gave her best advice on a range of issues. She was always curious, engaged and thoughtful," he said.
On the day of the queen's death, Trudeau got emotional during a tribute to the late monarch and even teared up when he said he "will miss her so."
Following a ceremony proclaiming the accession of King Charles III as the new sovereign a few days later, the prime minister noted that while the country mourns the queen, we must "look to the future."
"On behalf of the Government of Canada, we affirm our loyalty to Canada's new king, His Majesty King Charles III, and offer him our full support," Trudeau said.