Facebook Inc. will pay $130 million to establish an independent board charged with reviewing how the company moderates its content, providing long-term backing to its experiment in better policing the platform.

The money, which Facebook described as an “initial commitment,” is meant to cover six years of operations, including salaries for board members, office space and a staff including case managers, lawyers and human resources personnel. A corporate trust managed by financial services firm Brown Brothers Harriman will in...