Isaiah Castilla (he/him)

Chief Legal Counsel

Isaiah serves as legal counsel at the Partnership Project, where he supports and strengthens the organization’s compliance and legal work. He brings extensive experience advising nonprofits and social change organizations, with a focus on aligning legal strategy with mission-driven impact.

Most recently, Isaiah served as Managing Director at Arabella Advisors, where he partnered with changemakers to advance programs and initiatives. He previously served as General Counsel at Democracy Fund and Democracy Fund Voice, providing legal and strategic guidance on program development, compliance, and grantmaking to support efforts to strengthen U.S. democracy.