The former Millwall and Wolves manager lasted just 39 days in charge of the Millers
Championship bottom club Rotherham have lost their second manager of the season
Following defeat to Leeds on Saturday evening, Kenny Jackett has left the South Yorkshire club.
Jackett was appointed as the successor to Alan Stubbs, who was dismissed after Rotherham found themselves rock-bottom of the table.
The club describe Jackett's decision to leave the club as 'A Shock', but will make no further comment on the issue.
The Millers gave a spirited second half performance and almost snatched a point against Leeds at the New York Stadium on Saturday with Jackett encouraged by the performance of his side.
Even at this early stage, Rotherham sit 11 points adrift of safety and Jackett's successor must start picking up points quickly.
He started with a 1-0 reverse to Reading before a decent point against Ipswich before slumping to three consecutive defeats.
The club have had now had three different managers since divisive figure Steve Evans left 12 months ago.
Paul Warne will take temporary charge of first team matters. The Millers are away at Burton on Saturday.