It's designed to free up the existing institution which deals with new cases of sexual abuse, and ensure priests have proper access to their right of appeal.
The commission will be made up of seven bishops or cardinals, but Pope Francis has not yet named them.
More than 848 priests have been defrocked for sexually abusing minors since 2004.
Over 2,500 priests have received lesser punishments for child abuse over the same period.
The Holy Father has said he is taking a "zero tolerance" approach to sexual abuse in the Catholic Church.