Dumfries and Galloway Council made the announcement after SWestrans had earlier removed the morning service citing a lack of use.
Galloway and West Dumfries MSP Finlay Carson has welcomed the reinstatement after having raised concerns with the council that the removal of the bus service meant some residents in Castle Douglas would be left with no way of getting to the Health Centre for morning appointments.
Commenting, Mr Carson said: “I welcome the reinstatement of a morning bus service between Castle Douglas and the Health Centre.
“It is important that Dumfries and Galloway Council work with local communities to ensure that services are there for those who need them most.”
The service will recommence on August 21, and will initially operate as a free service.