Black has handled the role on an interim basis since the departure of Chang in November, just six months into his spell as director of comms.
Black will be responsible for all of the club's comms including managing the press office, PR, internal comms and photography.
Chang's departure came a month after the Daily Mail reported allegations that Chang threatened to revoke a blogger's season ticket due to his coverage of the club.
Chang denied he made the threats, but Liverpool MD Ian Ayre later apologised 'for any upset and distress this caused'.
The club denied Chang's departure was related to the incident and stated he left by mutual consent and had returned to the United States for family reasons.
Black joined the club in 2011 as head of internal comms after a role heading up comms for global management consultancy WYG.
Her previous roles include head of comms at NTL (now Virgin Media) and comms manager at Scottish Enterprise.
Ayre said of her appointment: ‘Susan brings a wealth of communications experience to the club and will be a key member of my senior executive team.’