"Last night I congratulated Donald Trump and offered to work with him on behalf of our country. I hope that he will be a successful president for all Americans," she said.
"This is not the outcome that we wanted.... and I'm sorry that we did not win this election. This is painful and it will be for a long time."
At one point, Clinton spoke to her younger supporters, saying that they may have career setbacks later, but to carry on.
"This loss hurts but please never stop believing that fighting for what's right is worth it," she said.
She also addressed her female supporters, who had hoped that she would make history by being elected the first female president.
"To all the women and especially the young women who put their faith in this campaign and in me, I want you to know that nothing has made me prouder than to be your champion. Now, I know, I know we have still not shattered that highest and hardest glass ceiling, but some day, someone will," she said.
That echoes her concession speech during the 2008 Democratic primary when she dropped out when it became clear that then-Sen. Barack Obama would be the party's nominee.