“I would like to thank Lee for his commitment and endeavour over the past 14 months,” said Sunderland’s Swiss chairman Kyril Louis-Dreyfus.
“We regret that we have had to take this decision, but felt immediate change was needed.
“We firmly believe this is in the best interests of Sunderland as we strive to earn promotion this season,” added Louis-Dreyfus, the youngest chairman in English football when he took over last February, at the age of 23.
Also, in this their fourth straight season back at third-tier level, Sunderland have played more games than both the top two, leaders Rotherham United and Wigan Athletic, who have four matches in hand.
Sunderland said in a statement: “The process to appoint a new head coach will commence immediately and a further update regarding the club’s interim coaching set-up will be communicated shortly.”
Excluding caretakers, the Wearsiders are looking for their 12th boss in 10 years to follow the line of Martin O’Neill, Paolo di Canio, Poyet, Dick Advocaat, Sam Allardyce, David Moyes, Simon Grayson, Chris Coleman, Jack Ross, Phil Parkinson and Johnson.
BBC Newcastle’s Sunderland reporter Nick Barnes
“In the light of Saturday’s 6-0 defeat, and Lee Johnson’s failure to address the obvious problems at half time, an inquest was inevitable.