Liturgy
QUESTION: Can the priest skip the homily and then have a layman deliver a homily after the final prayer at Mass?
ANSWER: The homily is optional during weekday masses, but mandatory during Sunday masses. Only priests are authorized to give the homily, with the exception of ordained deacons, who upon dispensation of the priest, may also be occasionally allowed to give the homily.
The Holy Mass ends after the final prayer, so any public sermon or discourse after that is not anymore officially part of the Mass.