The 28-year-old singer opened her show in Antwerp, Belgium, on Sunday night, by dedicating her performance to the victims.
"I want to start tonight by dedicating this entire show to everyone at Pulse nightclub last night," Adele told the audience as they applauded.
The "Hello" singer visibly choked up as she continued.
"The LGBTQ community, they're like my soulmates since I was really young, so I'm very moved by it," she explained, clearly upset.
The GRAMMY winner later attempted to lighten the mood with a little bit of self-deprecation.
"I didn't want to cry, really, because most of this tonight is pretty miserable -- because my songs are f**king miserable," she joked. "I do have two songs that sound happy, but they're not."
"This is an especially heartbreaking day for all of our friends, our fellow Americans, who are lesbian, gay, bisexual, or transgender," Obama said in his remarks. "The shooter targeted a nightclub where people came together to be with friends, to dance and to sing, and to live. The place where they were attacked is more than a nightclub -- it is a place of solidarity and empowerment where people have come together to raise awareness, to speak their minds and to advocate for their civil rights. So, this is a sobering reminder that attacks on any American, regardless of race, ethnicity, religion, or sexual orientation, is an attack on all of us, and on the fundamental values of equality and dignity that define us as a country.”
"In the face of hate and violence, we will love one another," he added. "We will not give into fear or turn against each other. Instead, we will stand united as Americans to protect our people and defend our nation and to take action against those who threaten us. God bless the Americans we lost this morning, may he comfort their families. May God continue to watch over this country that we love."