The Millers boss has paid the price for back-to-back defeats to Bolton and Charlton which has left them in the Sky Bet Championship relegation zone.
Redfearn was only appointed in October as Steve Evans' replacement and had 21 games in charge, where he managed just five wins.
Chairman Tony Stewart said: "It is with a heavy heart that we've parted company with Neil today.
"As we all know football is a results driven business and with 16 games to go our aim has to be to retain our Championship status.
"Everyone at the club wishes Neil well with his future career and thank him for his efforts and
endeavour.
"Our focus now is
100 per cent behind appointing a first team manager as soon as possible."
Redfearn was allowed to reshape his squad during the January transfer window, bringing in seven players, and appointed a new assistant manager on Thursday.
