Oldham are looking for a fifth manager in 12 months after sacking Laurent Banide.
The 51-year-old Frenchman only took over at Boundary Park on June 11 but has been dismissed with one League Two victory from nine games to his name.
Assistant Bouziane Benaraibi has also left the club.
"The club would like to thank the head coach and his assistant for their efforts whilst at Boundary Park over the summer and wish them well for the future," a statement read.
"An update on the new head coach will be made soon."
Banide took over in the summer after Pete Wild chose to leave. He had replaced Paul Scholes after his short-lived reign, with Wild having served as caretaker prior to that.
Frankie Bunn left Oldham in December last year.
At the time of Banide's appointment, Oldham chairman Abdallah Lemsagam had high hopes for the future, saying "I'm delighted to welcome Laurent to
Oldham Athletic.
"He brings a lot of experience to this club and I'm looking forward to working alongside him the 2019-20 campaign. I believe Laurent is a fantastic coach and is the right man to take this club forward going into the new season."