The Canadian manager had been battling throat cancer since 2013, and underwent surgery to remove the cancerous tumor in his throat.
This was the second time Celine's husband was diagnosed with the disease, having first battled throat cancer in 1999.
On her official website, the Celine released the following official statement: 'René Angélil, 73, passed away this morning at his home in Las Vegas after a long and courageous battle against cancer. The family requests that their privacy be respected at the moment; more details will be provided at a later time.'
The couple were together for almost 30 years, having started dating in 1987
Celine met René when she was only 12 years old, and they started dating in 1987. They later became engaged in 1991, and tied the knot three years later, in December 1994, at Notre-Dame Basilica in Montreal, Quebec.
René was both her manager and her mentor, and even helped fund her first record, La voix du bon Dieu, by mortgaging his home.
They have three children together - René-Charles, 14, and five-year-old twins Nelson and Eddy - and René also had three children from previous relationships.
The couple and their twins in 2011
The couple had recently celebrated their 21st wedding anniversary in December. The 47-year-old singer marked the special occasion by posting a cute throwback picture on her Instagram account, of the two holding hands on their wedding day.
Speaking to Entertainment Online in May, Celine talked about the indefinite leave of absence she took from her Las Vegas residency in 2014, after René's surgery.
'It's not hard to take time off. It's not hard to be with him, obviously. It's not hard to be with the family and the kids', the singer said. 'It's hard because life imposes things on you.'
She later returned to the stage in August, after being urged to by her husband, who told her to go back and 'still share your passion'.
'He's been there for me all my life, and I've been there for him all my life. There's a part of me that never really left the stage. I wanted to be there but I needed to be someplace else which was much more important at that time. To be by his side. To be by my family.'
The singer has cancelled her shows until late February.
Our thoughts are with you and your family at this difficult time, Celine.