Dion was born in Charlemagne, Quebec, on March 30, 1968, 24 kilometers northeast of Montreal, the youngest of 14 children of Thérèse, a homemaker, and Adhémar Dion, a butcher, both of French-Canadian descent.

On 13 August 1973, at the age of five, the young Céline made her first public appearance at her brother Michel's wedding, where she performed Christine Charbonneau's song "Du fil, des Aiguilles et du Coton".

At age 12, she collaborated with her mother and her brother Jacques to write and compose her first song, "Ce n'était qu'un rêve", whose title translates as "It Was Only a Dream" or "Nothing But A Dream". Her brother Michel sent the recording to music manager René Angélil, whose name he discovered on the back of a Ginette Reno album.

By 1983, in addition to becoming the first Canadian artist to receive a gold record in France for the single "D'amour ou d'amitié" ("Of Love or Friendship"), Dion had also won several Félix Awards, including "Best Female performer" and "Discovery of the Year".

Dion underwent dental surgery to improve her appearance and was sent to the École Berlitz in 1989 to polish her English.

In 1989, during a concert on the Incognito tournée, she injured her voice. She consulted the otorhinolaryngologist William Gould,who gave her an ultimatum: have immediate surgery on her vocal cords or do not utilize them at all for three weeks. Dion chose the latter and underwent vocal training with William Riley.

Angélil and Dion married in an extravagant wedding ceremony on 17 December 1994, which was broadcast live on Canadian television.

Dion was asked to perform "The Power of the Dream" at the opening ceremony of the 1996 Atlanta Olympic Games.

In 1999, Dion received a star on Canada's Walk of Fame and was inducted into the Canadian Broadcast Hall of Fame.

In August 2008, she received an honorary doctorate in music from the Université Laval in Quebec City.

On 22 August 2008, Dion presented a free outdoor concert, mostly in French, on the Plains of Abraham, in Québec City, Canada, for the 400th anniversary of Québec City.The celebration gathered approximately 490,000 people.

In May 2009, Dion was named the 20th best-selling artist of the decade and the second-best-selling female artist of the decade in the United States, selling an estimated 17.57 million copies of her albums there since 2000.

In January 2010, The Los Angeles Times presented its annual list of the top ten largest earners of the year, revealing Dion took the top spot for the entire decade, with $US747.9 million in total revenue from 2000–2009.

On 13 August 2014, Dion announced the indefinite postponement of all her show business activities, including her concert residency at Caesars Palace in Las Vegas, and the cancellation of her Asia Tour, because of the worsening of her husband's health after he underwent the removal of a cancerous tumor in December 2013.

Aline is a 2021 French-Canadian musical comedy-drama film co-written, directed by, and starring Valérie Lemercier. A fictionalized portrayal of the life of Céline Dion, Lemercier plays "Aline Dieu", a Canadian singer who rises to international superstardom. Production companies are Rectangle Productions, Gaumont, TF1 Films Production,De L'Huile, Caramel Film and Belga Productions.