- Robert Redford - The Academy Award-winning actor and environmentalist has been a vocal opponent of horse slaughter. He narrated a documentary called "Slaughterhouse" that exposed the cruel conditions of horse slaughterhouses.
- Sheryl Crow - The Grammy Award-winning singer-songwriter has used her music and celebrity platform to raise awareness about horse slaughter. She wrote and recorded the song "Homesick" to bring attention to the issue.
- Willie Nelson - The legendary country music singer and songwriter has been a longtime advocate for animal welfare, including opposing horse slaughter. He has participated in protests and spoken out against the practice.
- Bo Derek - The actress and animal rights activist has been actively involved in efforts to end horse slaughter. She has testified before Congress on the issue and has worked with various animal welfare organizations.
- Hayden Panettiere - The actress and singer has been an outspoken advocate for animal rights, particularly focusing on horse slaughter. She has worked with the Humane Society of the United States and other organizations to raise awareness and support legislation to end horse slaughter.
- Kristin Chenoweth - She has spoken out against horse slaughter in the past. In 2017, she wrote a letter to the U.S. Department of Agriculture, urging them to shut down horse slaughter plants in the United States.
- Joaquin Phoenix - He has spoken out against horse slaughter and has even participated in protests. In 2019, he joined a protest outside the U.S. Department of Agriculture building in Washington, D.C., to call for an end to horse slaughter.