The Black Cats have parted company with the 40-year-old just 24 hours after their 6-0 humiliation at the hands of Bolton.
The former Bristol City boss leaves his role on Wearside with Sunderland third in the table and two points behind league leaders Rotherham.
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Johnson was appointed Sunderland boss in December 2020 and guided the club to Papa John’s Trophy final success in 2021.
A run to semi-final stage of this season’s Carabao Cup was also a highlight of his time in charge – a run that was only halted by Arsenal.
But with promotion back to the Championship the Black Cats’ main aim, Saturday’s 6-0 hammering at the University of Bolton Stadium proved Johnson’s final match in charge.
It was his side’s fourth heavy defeat on the road this term, with telling loses at Pompey (4-0), Rotherham (5-1) and Sheffield Wednesday (3-0) not looking favourably on the powers that be at the Stadium of Light.
Sunderland also suffered a heavy 3-1 home defeat against Lincoln earlier this month, before victory was secured against the Blues on January 22.