Gregory Castle

One of the founders of Best Friends Animal Society, Gregory Castle served as the CEO of Best Friends from 2009 to 2018. Since the mid-1980s, Gregory has been a recognized leader in animal welfare and a voice of reason and reconciliation among grassroots rescue groups, animal shelters and national animal organizations.


Mr. Castle is responsible for the creation of No More Homeless Pets in Utah, which evolved into No-Kill Utah (NKUT), a Best Friends–led coalition of animal welfare and rescue organizations and animal lovers collaborating to deliver aggressive spay/neuter, adoption and public awareness programs to help the state’s homeless pets. Mr. Castle’s efforts have fundamentally changed the state of animal welfare in Utah, which is currently on a trajectory to become a no-kill state by 2019. The coalition is a model for cooperative efforts in the humane community throughout the country.


As CEO of Best Friends, Mr. Castle focused the organization’s resources on efforts that help communities nationwide move toward no-kill and set the stage for a national campaign to end the killing in shelters throughout the country by 2025.


As CEO emeritus, he has now shifted his energy and attention to the inter-organizational 2025 National Steering Committee led by Best Friends, bringing to the role his decades of experience, knowledge and strong relationships across the animal welfare world. As a universally respected leader, he is guiding Best Friends’ collaborative relationships with other no-kill leaders to help achieve the 2025 no-kill goal. He is also continuing his important work as a founder and ambassador with our major donors team, as well as fulfilling an internal consultancy role for Best Friends.