The Clinton campaign released a video on Thursday with his announcement. The president also intends to campaign with Clinton next week in the state of Wisconsin.
Clinton was named the presumptive Democratic presidential nominee earlier this week after clinching the required number of delegates and earning major wins in primaries in New Jersey and California.
"Look, I know how hard this job can be. That's why I know Hillary will be so good at it," Obama said. "In fact, I don't think there's ever been so qualified to hold this office."
Rival Bernie Sanders has not indicated that he will drop out of the race, and has previously stated that he intends to continue through the Democratic convention in July, hoping to sway superdelegates currently supporting Clinton.
After meeting with President Obama on Thursday morning, Sanders did indicate that he could be softening his stance. While he did not say he intends to drop out of the race, Sanders did say he would work with Clinton to ensure that presumptive Republican nominee Donald Trump does win the general election in November.
"If we all come together in common effort, I'm convinced we con't just win in November," Obama said, "we'll build on the progress that we've made and we will win a brighter future for this country that we love."