Christian Bale, seen here at "The Dark Knight Rises" New York premiere on July 16, 2012, in New York, was among those sending messages of sympathy to Aurora, Colo.
Bale, who plays Batman in "The Dark Knight Rises," said: "Words cannot express the horror that I feel. I cannot begin to truly understand the pain and grief of the victims and their loved ones, but my heart goes out to them."
Keep clicking to see how other stars and prominent figures have reacted to the tragedy.
Christopher Nolan,director of "The Dark Knight Rises," expressed "profound sorrow" on behalf of the cast and crew about "the senseless tragedy that has befallen the entire Aurora community."
"I believe movies are one of the great American art forms and the shared experience of watching a story unfold on screen is an important and joyful pastime," Nolan said. "The movie theater is my home, and the idea that someone would violate that innocent and hopeful place in such an unbearably savage way is devastating to me."
Actor Gary Oldman, who plays Commissioner James Gordon in the Batman trilogy, was the first to issue a statement.
"My prayers and deepest sympathies are with the victims and their families of this horrific act," he said.
Actress Anne Hathaway, who plays Catwoman in "The Dark Knight Rises," released this statement: "My heart aches and breaks for the lives taken and altered by this unfathomably senseless act. I am at a loss for words how to express my sorrow. My thoughts and prayers are with the victims and their families."
President Obama met Sunday with victims of Friday's mass shooting in Aurora.
"I confessed to them that words are always inadequate," Mr. Obama said, following the meeting, but added that his "main task was to serve as a representative of the entire country and we think of them at this moment and we will continue to think of them each and every day."
The president suspended his campaign's activities in Colorado during the weekend out of respect to the shooting victims.
GOP presidential hopeful Mitt Romney, who also suspended campaigning all weekend, said: "Ann and I are deeply saddened by the news of the senseless violence that took the lives of 15 people in Colorado and injured dozens more. We are praying for the families and loved ones of the victims during this time of deep shock and immense grief. We expect that the person responsible for this terrible crime will be quickly brought to justice."
Pope Benedict XVI mentioned the tragedy in his Sunday sermon at the papal summer residence at Castel Gandolfo, in the hills south of Rome. "I share the distress of the families and friends of the victims and the injured, especially the children. Assuring all of you of my closeness in prayer, I impart my blessing as a pledge of consolation and strength in the risen Lord," said the leader of the Roman Catholic Church.
In a written message to President Obama, Britain's Queen Elizabeth II said, "I was saddened to learn of the tragic loss of life earlier today in Denver, Colo. Prince Philip joins me in extending our heartfelt sympathy to you and the people of America at this time."
"My thoughts and prayers are with the families of those killed and I wish the many who were injured a swift and full recovery," she added.
"Jill and I were shocked to learn of the tragedy in Aurora, Colo., this morning," Vice President Joe Biden said on Friday.
"The reason this is so deeply felt by all Americans is that, but for the grace of God, the victims could have been any one of our children, in any one of our towns. It is every parent's worst nightmare to receive 'that phone call' and to sit by their child's bedside, praying. We know what it's like to wait and wonder and the helplessness a parent feels at this moment. Our hearts go out to each and every person who is suffering right now as a result of this terrible event. The prayers of an entire nation are with the victims and their families. We stand with the city of Aurora and the state of Colorado in mourning."
Singer, dancer and actress Julianne Hough said: "My love & prayers are with all the families that have been affected by the horrible, unspeakable torment from last nights shooting! My heart is so heavy! Don't take for granted the air we breath the people that touch us and the people we touch!"
Kim Kardashian wrote: "Just landed in Miami & heard the tragic news re the shooting in Aurora. This is so devastating & beyond words. Nothing is worth causing so much pain to so many people. I'm angry and heartbroken."
Actor, veteran and "Dancing with the Stars" winner J.R. Martinez wrote: "Waking up to the #tragic news of the #theatershooting in #aurora CO. Sickening to say the least. No excuses or trial~max penalty for him."
Actor Jeremy Renner said: "It crushes my heart and my heart goes out to all the families. This will have nothing to do with how well movies do now at the box office - cinema is so small compared to what has just happened."