David Hopkin has stood down as Bradford manager after just six months in charge of the Sky Bet League One side.
Saturday's 3-2 defeat at Walsall left the Bantams 23rd in the table, three points from safety and four above bottom side AFC Wimbledon.
Hopkin said in a statement: "I am disappointed but feel the time is right for me to step aside and allow someone to come in and attempt to keep the club in League One.
"I have given my all over the past six months. I took on a tough job and have left no stone unturned in my efforts to help us climb the table.
"The club means a great deal to me, as a former player, and that is why I have made this decision – with a quarter of the season remaining.
"I would like to take this opportunity to thank the incredible Bradford City fans. This has been a hugely difficult season for everyone involved and they have shown me a great deal of support. I wish the club the very best for the future."
Interim chief executive Julian Rhodes added: "Our thanks must go to David, who has put in a great deal of effort since taking over the reins last year.
"I know just how hard he has worked, in extremely difficult circumstances, and he leaves with a great amount of respect. On behalf of everyone at the club, we wish David and his family all the best for the future."
Martin Drury has been installed as caretaker manager for Saturday's game against Portsmouth. He will be assisted by Anton McElhone.
