Malcolm Turnbull recalls the moment he knew wife Lucy was 'the one'

Former Australian Prime Minister Malcolm Turnbull has spoken about his wife Lucy during a TV interview on Monday night, calling her the "love of my life".

Turnbull sat down with Leigh Sales on ABC's The 7.30 Report to talk about his autobiography A Bigger Picture, which is out now.

He said he used to imagine who he would marry when he was a child, and an image would pop into his head of someone. When he met Lucy, he said he knew she was 'the one'.

"I've always had a stronger sense of Lucy and me than I do of me," he told Sales.

"We've been together for so long - for over 40 years we've been married... I think I was always meant to meet Lucy.

"I used to, when I was a kid, I used to sometimes think of who I would marry, and this sort of image of a girl who I imagined was more or less my age would come into my mind.

"When I met Lucy and got to know her and saw her childhood pictures, that was the little girl ... just from the time I met her, I know that this was the love of my life."

The pair met when Lucy was 19 and Turnbull 23. Their first date was dinner with former Premier of NSW Bob Carr and his wife Helena.

The couple were married on March 22, 1980 in the UK, where Turnbull was attending the University of Oxford.

They have two children - Alex, 38, and Daisy, 35.

Lucy served as Lord Mayor of Sydney from 2003 until 2004, the first woman to hold the position, and has worked in business and philanthropy.

The couple reside in Sydney's eastern suburbs and are proud grandparents of four grandchildren.

Purchase your copy of Malcolm Turnbull's autobiography A Bigger Picture at your favourite book retailer.