The Seasiders have acted swiftly to replace the outgoing Terry McPhillips, whose resignation was announced on the eve of pre-season.
And the club have confirmed that Grayson is set to return to the club where he cut his managerial teeth back in 2005.
A former player at Bloomfield Road, the 49-year-old spent three years in the dugout with Blackpool before going on to manage Leeds United, Huddersfield Town and Preston North End – before arriving at Sunderland in 2017.
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Grayson lasted just four months on Wearside before being dismissed on October 31, following a 3-3 draw with Bolton Wanderers.
But he will now return to the Stadium of Light with his new side in the 2019/20 League One campaign – with the Seasiders set to visit the North East on December 14.