Speaking to a large crowd of mostly women, Lovato said Thursday she was voting for Clinton because she "completely embodies the concept" of female empowerment, CNN Politics reports.
"And, last but not least, I'm voting for her because I truly believe there is nobody more qualified to run this country -- our country -- than our secretary of state, Hillary Clinton," the "Confident" singer said before inviting the candidate to join her onstage.
Clinton in turn complimented Lovato for giving hope and "positive reinforcement," to her fans and others throughout her career. "I'm thrilled you're here, lending your voice and your example to our efforts to get people to get out and caucus," she told the singer.
"I don't think there's a woman more confident than Hillary Clinton," Lovato said at the rally ahead of the state's Feb. 1 caucus.
Clinton is in a close race in Iowa with Vermont Sen. Bernie Sanders, who a CNN poll reports leads her 51 percent to 43 percent. Former Maryland Gov. Martin O'Malley is also seeking the Democratic nomination.
Billboard reports about 2,000 supporters showed up to the Iowa City rally, at which Lovato also performed her hit single "Confident."