Irish FA Chief Executive Patrick Nelson says Ian Baraclough's "overall record of results on the pitch" led to his sacking.
The IFA's Board reached its decision on Thursday night before confirming on Friday that it had parted company with the 51-year-old.
Pressure had been mounting on Baraclough - who was named as Michael O'Neill's successor in June 2020 - following another miserable Nations League campaign.