Moore, 73, had been hospitalized since March 13 at Duke University Medical Center in Durham, N.C., because of a pulmonary condition. According to the university, funeral arrangements are pending.
Moore stepped down as athletics director March 20 because of health reasons. Bill Battle, who was introduced as Moore's replacement March 21, told a Birmingham radio station last week Moore needed a lung transplant.
“The University of Alabama and the world of intercollegiate athletics have lost a legend, and I have lost a dear friend," Battle said in a statement released by the school. "My heart goes out to his family and close friends in this time of sadness. After a time of grieving, we can begin to celebrate Mal’s life, as his legacy will last for generations."
The news spread quickly across social media Saturday, as current and former Alabama athletes and staff expressed sorrow.
Alabama All-America center Barrett Jones, who has completed his college career, posted: "His legacy is something that will affect many generations to come. I'm a better man today because I knew Coach Moore. So honored to know him."
Rising sophomore linebacker Reggie Ragland posted: "RIP Mal Moore this next season is for you sir."
Alabama basketball senior Andrew Steele posted: "RIP to Mal Moore. He always supported our program and was so down to earth for his position. His mark on our university will forever be felt."
Former Alabama basketball coach Mark Gottfried, who stepped down Jan. 26, 2009, amid heavy criticism from the Crimson Tide fan base, posted about Moore, too. Gottfried is now North Carolina State's basketball coach.
"Prayers go out to family of Mal Moore Spent Wed w/him at Duke Medical one of best people I've known loved him as person & boss at Alabama," Gottfried posted.
Even Gov. Robert Bentley released a statement about Moore: "Coach Moore will be deeply missed. I've known Mal for over 30 years and have always considered him a good friend as well as a good man."
At Alabama's baseball game at Auburn on Saturday, Crimson Tide baseball players wrote "CMM" on the right side of their caps above the brim in honor of Moore. A moment of silence was observed for Moore before the game at Plainsman Park.
Alabama's softball team announced plans for players and coaches to wear black ribbons with "MM" on them Saturday when the Crimson Tide plays at Texas A&M. A moment of silence was observed before the softball game, too.
Jay Jacobs, athletics director at rival Auburn, released a statement expressing sadness.
“I’m extremely saddened by the passing of my friend and colleague, Mal Moore," Jacobs said in the statement. "He served his alma mater with grace and dignity, and spent a majority of his life giving to the university that he loved.
"Mal was an outstanding leader, fierce competitor and most important, an outstanding human being. He will be missed, but his legacy at Alabama will live on forever. On behalf of the Auburn Family, our thoughts and prayers are with his daughter, Heather, the extended Moore family, as well as everyone associated with the University of Alabama.”
Moore was born Dec. 19, 1939, in Dozier. He was one of seven children and graduated from Alabama in 1963 with a degree in sociology. He also earned a master's degree in 1964 from Alabama in secondary education.
He is survived by daughter Heather Cook, son-in-law Steve Cook, granddaughter Anna Lee Cook and grandson Charles Cannon Cook. They live in Scottsdale, Ariz.
Moore's wife of 41 years, the former Charlotte Davis, died in January 2010 at age 71 after a long illness.
Moore was part of 10 national football championships as a player, coach and athletics director.
He was part of the first recruiting class by legendary coach Bear Bryant in 1958 and was a backup quarterback through 1962. One of his teammates was Battle.
After spending the 1963 season as an assistant coach at Montana State, he worked as an assistant under Bryant during 1964-82. He had hoped to succeed Bryant, but then-university president Joab Thomas hired former Tide player Ray Perkins instead.
Moore left Alabama and was an assistant coach at Notre Dame during 1983-85 before joining the Gene Stallings' staff with the NFL's Cardinals in St. Louis and Phoenix in 1986-89. When Stallings accepted the head coaching job at Alabama in 1990, Moore returned to campus as offensive coordinator through 1993.
Moore served as associate athletics director from 1994 until he was hired as athletics director in 1999 by then-university president Andrew Sorensen, who died in 2011.
Moore's two most recognized accomplishments are the hiring of football coach Nick Saban in 2007 and the upgrade of the university's athletics facilities.
After Saban turned down Moore's job offer, Moore continued to court the coach, eventually landing him. Saban has directed Alabama to three national championships, and on Saturday, he said Moore "was the number one reason we decided to make the move to Tuscaloosa."
Moore directed building projects of more than $240 million combined, according to the university. That included expansion of Bryant-Denny Stadium; new softball and soccer stadiums; renovation of Coleman Coliseum, Foster Auditorium and the athletic complex; and a new training facility. He also oversaw the renovation of Bryant Hall, the former dorm for football and basketball players, into an academic center.
In 2007, Alabama named its athletics facility for him. In 2011, he was inducted into the Alabama Sports Hall of Fame. The National Football Foundation awarded him the John L. Toner Award in 2012 as the nation’s best athletics director.
“I cannot adequately express what the University means to me," Moore said in a news release March 20 announcing his retirement. "It has been a part of my life for more than 50 years, and I feel honored to have served the Crimson Tide as a player, coach and administrator. I am so appreciative of the University administration, coaches, staff, student-athletes and fans who have made my tenure as director so very meaningful, memorable and special.”