The action gets under way on Friday evening when Irish side Waterford host Heart of Midlothian Colts while Connah's Quay Nomads v Cove Rangers is live on S4C on Saturday evening.
The full list of third-round ties is as follows...
Friday 6 September, 2019
Waterford v Heart of Midlothian Colts - Regional Sports Centre, kick-off 7.45pm
Saturday 7 September, 2019
Airdrieonians v Bohemians - Penny Cars Stadium, kick-off 1.00pm
Clyde v Queen of the South - Broadwood Stadium, kick-off 3.00pm
Connah’s Quay Nomads v Cove Rangers - Deeside Stadium, kick-off 5.15pm (Live on S4C)
Dundee United v Arbroath - Tannadice Park, kick-off 3.00pm
Dunfermline Athletic v Alloa Athletic - East End Park, kick-off 3.00pm
Formartine United v Glenavon - North Lodge Park, kick-off 3.00pm
Inverness Caledonian Thistle v Greenock Morton - Caledonian Stadium, kick-off 3.00pm
Kelty Hearts v Solihull Moors - New Central Park, kick-off 3.00pm
Montrose v Partick Thistle - Links Park, kick-off 3.00pm
Raith Rovers v Falkirk - Stark’s Park, kick-off 3.00pm
St Mirren Colts v Stirling Albion - Simple Digital Arena, kick-off 3.00pm
Stenhousemuir v The New Saints – Ochilview Park, kick-off 3.00pm
Wrexham v Ayr United - Racecourse Ground, kick-off 3.00pm
Sunday 8 September, 2019
Dundee v Elgin City - Kilmac Stadium at Dens Park, kick-off 3.00pm
Wednesday 18 September, 2019
Ballymena United v Rangers Colts - Ballymena Showgrounds, kick-off 7.45pm
In the event of a draw after 90 minutes, matches will be decided by a penalty shoot-out
Next round: Fourth-round ties are scheduled for the weekend of October 12/13