Huddersfield have parted company with manager Andy Ritchie by mutual consent.
Despite winning two of their last three games, Town sit 14th in the League One table and are 10 points away from a play-off place with six games remaining.
Director of Football Development Gerry Murphy will take over as caretaker manager while the search for a replacement begins.
Chairman Ken Davy told the club's official website: 'For whatever reason the reality is that despite an increase spend and new signings, we have not progressed as we all hoped this season. We will now take a fresh look at our options.
'Huddersfield has some great supporters and tremendous potential as well as great history - we need to find someone who can harness these elements as we celebrate the club's hundred years.'