The shock announcement was made this morning following a meeting with the 42-year-old former Coventry boss where it was agreed it would be best to take the club in ‘a different direction.’
In a statement, the Highbury club said: “Fleetwood Town would like to thank Steven for his professionalism and effort during his nine months at Highbury, particularly in successfully maintaining the club’s League One status last season.
“Our focus will now turn to the prompt recruitment of a new manager to take the club forward.”
Pressley was reluctant to talk about the reasons behind his decision to quit with 11 days to go to the start of the season.
He said: “It is not something that I want to discuss or go into at this moment in time.
“There are a number of factors involved in it - now is not the time.”
Chairman Andy Pilley was due to make a statement later.