Baraclough, 49, has served as the country’s Under-21 boss for the last three years.
His promotion to the senior role was confirmed on Saturday (June 27) by the Irish Football Association.
O’Neill joined Championship side Stoke City in November 2019 after eight years in charge of Northern Ireland.
He initially combined the position with the national team job before stepping down in April this year.
— Northern Ireland (@NorthernIreland) June 27, 2020
O’Neill had hoped to lead the team into the Euro 2020 play-offs, but decided against carrying on when they were delayed due to the coronavirus pandemic.
Baraclough will instead have that task, with Northern Ireland to play Bosnia-Herzegovina in the semi-finals on October 8.
The former Motherwell and Scunthorpe United manager’s first game in charge will come before that, though, with an away fixture against Romania in the Nations League on September 4.
Get breaking news alerts.
You have already subscribed