Reynolds was born Mary Frances Reynolds in El Paso, Texas, the second child of Maxine N. (née Harmon; 1913–1999) and Raymond Francis Reynolds (1903–1986), who was a carpenter for the Southern Pacific Railroad. She has Scotch-Irish and English ancestry. Reynolds was a Girl Scout and a troop leader (a scholarship in her name is offered to high-school age Girl Scouts). Her family moved to Burbank, California, in 1939, and she was raised in a strict Nazarene faith. At age sixteen, while a student at Burbank's John Burroughs High School, Reynolds won the Miss Burbank beauty contest, a contract with Warner Bros., and acquired a new first name.
Reynolds regularly appeared in movie musicals during the 1950s and had several hit records during the period. Her song "Aba Daba Honeymoon" (featured in the film Two Weeks with Love  as a duet with Carleton Carpenter) was a top-three hit in 1951. Her most high-profile film role was in Singin' in the Rain (1952) as Kathy Selden. In Bundle of Joy(1956) she appeared with her then-husband, Eddie Fisher.
Her recording of the song "Tammy" (from her film Tammy and the Bachelor (1957)) earned her a gold record, and was the best-selling single by a female vocalist in 1957. It was number one for five weeks on the Billboard pop charts. In the movie (the first of the Tammy film series), she co-starred with Leslie Nielsen.
In 1959, Reynolds recorded her first album for Dot Records, simply called Debbie, which included her own selection of twelve standards including "S'posin'", "Moonglow", "Mean To Me", and "Time After Time". Bing Crosby paid tribute to Reynolds in the sleeve notes accompanying the album thus:
Someone recently said, and with reasonable accuracy I would think, that good singers make good actors. Evidence in support of this belief is available in the recent performances of Sinatra and Martin, for instance, but I would like to put forth also the proposition that the reverse is quite true: good actors make good singers. Assuming they can carry a tune. We all know that Debbie is better than a good actress—she's VERY good, and we all know she can sing with a lilt and a listenable quality that's genuinely pleasant and agreeable. Witness "Tammy". It was small surprise to me then that when I listened to this beautiful album she has etched for Dot, I found myself captivated and enchanted. Quite obviously Debbie had spent a great deal of time selecting the songs to be included, because she's made them her own, and invested them with a sincerity that's inescapable—of contrasting moods to be sure, but the moods are there, and to me, mighty effective. And that, mes amis, is artistry.
Reynolds also scored two other top-25 Billboard hits with "A Very Special Love" (1958) and "Am I That Easy to Forget" (1960) — a pop-music version of a country-music hit made famous by both songwriters Carl Belew (in 1959), Skeeter Davis (in 1960), and several years later by singer Engelbert Humperdinck. She has released several albums of both her vintage performances and her later recordings.
During these years, she also headlined in major Las Vegas showrooms.
Her starring role in The Unsinkable Molly Brown (1964) led to a nomination for the Academy Award for Best Actress. She then portrayed Jeanine Deckers in The Singing Nun (1966).
In what Reynolds has called the "stupidest mistake of my entire career", she made headlines in 1970 after instigating a fight with the NBC television network over cigarette advertising on her eponymous television series; NBC cancelled the show.
Reynolds made her Broadway debut in 1973 in a revival of Irene, a musical first produced 60 years before. For that production, she received a Tony nomination. She toured with Harve Presnell in Annie Get Your Gun, then wrapped up the Broadway run of Woman of the Year in 1983. In the late 1980s, Reynolds repeated her role as Molly Brown in the stage version of The Unsinkable Molly Brown, first opposite Presnell (repeating his original Broadway and movie role) and later with Ron Raines.
Reynolds continues to make appearances in film and television. She played Helen Chappel Hackett's mother, Deedee Chappel, on an episode of Wings titled, "If It's Not One Thing, It's Your Mother", which originally aired on November 22, 1994. From 1999 to its 2006 series finale, she played Grace Adler's ditzy mother, Bobbi Adler, on the NBC sitcom Will & Grace (1998–2006), which earned her anEmmy Award nomination for Outstanding Guest Actress in a Comedy Series in 2000. She also plays a recurring role in the Disney Channel Original Movie Halloween town film series as Aggie Cromwell. Reynolds made a guest appearance as a presenter at the 69th Academy Awards in 1997.
Reynolds appeared in her West End show Debbie Reynolds: Alive and Fabulous. In June 2010 she replaced Ivana Trump answering reader queries for the weekly paper Globe.
Reynolds' new tell-all autobiography, Unsinkable – a play-on-words of her 1964 film The Unsinkable Molly Brown – was published by William Morrow and Company on April 2, 2013.
Reynolds won the National Board of Review Award for Best Supporting Actress for her role in The Catered Affair (1956).
She has received various nominations for awards including: an Academy Award nomination for Best Actress for The Unsinkable Molly Brown (1964), a Golden Globe Awardnomination for Best Actress – Television Series Musical or Comedy for The Debbie Reynolds Show (1970), a Golden Globe nomination for Best Actress – Motion Picture Musical or Comedy for Mother (1996) and an Emmy Award for Outstanding Guest Actress in a Comedy Series, for her role of Bobbi Adler in the sitcom Will & Grace (2000). In 1996 and 1997, she received the Lifetime Achievement Award in Comedy, in the American Comedy Awards.
Her foot and hand prints are preserved at the Grauman's Chinese Theatre in Hollywood, California. She also has a star on the Hollywood Walk of Fame at 6654 Hollywood Boulevard and a Golden Palm Star on the Palm Springs, California, Walk of Stars dedicated to her.
In November 2006, Reynolds received the "Lifetime Achievement Award" from Chapman University (Orange, California). On May 17, 2007, she was awarded an honorary degree ofDoctor of Humane Letters from the University of Nevada, Reno, (Reno, Nevada) where she had contributed for many years to the film-studies program.
Reynolds last CD was a Christmas Record with the late Donald O'Connor entitled "Chrissy the Christmas Mouse". It received rave reviews and was arranged by Angelo DiPippo and produced by Dr. Fillardi.
Reynolds has amassed a large collection of movie memorabilia, beginning with the landmark 1970 Metro-Goldwyn-Mayer auction, and displayed them, first in a museum at her Las Vegas hotel and casino during the 1990s and later in a museum close to theKodak Theater in Los Angeles. On several occasions, she has auctioned off items from the collection.
The museum was to relocate to be the centerpiece of the Belle Island Village tourist attraction in the resort city of Pigeon Forge, Tennessee, but the developer went bankrupt. The museum itself filed for Chapter 11 bankruptcy in June 2009.
Todd Fisher, Reynolds' son, announced that his mother was "heartbroken" to have to auction off her collection. It was valued at $10.79 million in the bankruptcy filing. The Vancouver Sun reported that Profiles in History has been given the responsibility of conducting a series of auctions beginning in June and continuing into December 2011. Among the "more than 3500 costumes, 20,000 photographs, and thousands of movie posters, costume sketches, and props" to be sold are Charlie Chaplin's bowler hat andMarilyn Monroe's white "subway dress", whose skirt is lifted up by the breeze from a passing subway train in the film The Seven Year Itch (1955).
On June 18, 2011, the subway dress was sold for $4.6 million, far in excess of pre-auction estimates of $1–2 million. Another Monroe dress, which she wore in Gentlemen Prefer Blondes, fetched $1.2 million, four times the upper pre-sale expectation.
Debbie Reynolds has been married three times. Her first marriage was to singer Eddie Fisher in 1955. They are the parents of Carrie and Todd Fisher. A public scandal ensued when Fisher and Elizabeth Taylor fell in love following the death of Taylor's then-husband Mike Todd, and Reynolds and Fisher were divorced in 1959. In 2011, first on The Oprah Winfrey Show only weeks before Elizabeth Taylor's death from congestive heart failure, Reynolds explained that she and Taylor happened to be traveling on the ocean liner Queen Elizabethat the same time when they made up. Reynolds sent a note to Taylor's room, and Taylor sent a note in reply asking to have dinner with Reynolds and end their feud. The two reconciled, and, as Reynolds put it, "...we had a wonderful evening with a lot of laughs".
Her second marriage, to millionaire businessman Harry Karl, lasted from 1960 to 1973. He was previously married to Marie McDonald. Reynolds later found herself in financial difficulty because of Karl's gambling and bad investments.
Reynolds was married to real estate developer Richard Hamlett from 1984 to 1996. They purchased Paddlewheel Hotel & Casino, a small hotel and casino in Las Vegas, but it was not a success. In 1997, Reynolds was forced to declare bankruptcy.
Since 1955, Reynolds has been active in the Thalians Club, a charitable organization, devoted to children and adults with mental health issues. In 2011 she stepped down after 56 years of involvement, and is now an emeritus member.
In keeping with the celebrity tradition of the Shenandoah Apple Blossom Festival of Winchester, Virginia, Reynolds was honored as the Grand Marshal of the 2011 ABF that took place from April 26 to May 1, 2011.