Add Kristen Bell to the ever-growing list of celebrities and politicians speaking out in favor of marriage equality.

The "House of Lies" actress is the latest to film a video ad for the Human Rights Campaign's (HRC) Americans for Marriage Equality effort. "It breaks my heart to know that millions of gay Americans still can't marry the one they love, and I can," Bell, who will next be seen opposite Bradley Cooper in this summer's "Outrun," says in the new clip. "That makes no sense."

Bell's efforts earned the praise of HRC President Joe Solmonese. "Every day committed and loving gay and lesbian couples face the unfair reality that marriage is out of the question for them," he said in an email statement. "Kristen Bell, like a majority of Americans, recognizes the injustice of this discrimination, and the harm it inflicts on families across the country."

This isn't the first time the 31-year-old actress has spoken out in favor of lesbian, gay, bisexual and transgender (LGBT) rights. Earlier this month, she told The Advocate that she and fiance Dax Shepard would hold off on tying the knot until until same-sex marriage is legal throughout the United States. "The reason we're not rushing to get married is because I don't feel appropriate taking advantage of a right that's denied to my best friends," said Bell, who names openly gay "Star Trek" actor Zachary Quinto as a confidante. "Dax and I have talked about it a lot, and this issue is very important to both of us. We're just standing up for what we believe in."

Among those who've also filmed spots for HRC are musician Jason Mraz, Academy Award winner Mo'Nique and Washington Gov. Chris Gregoire. Check out these as well as other marriage equality videos below: