The Latics were among the favourites for promotion following a strong summer of recruitment at Boundary Park.
But Saturday’s 3-0 loss at Bromley left the club winless since the second weekend of the season.
Pressure had been on the manager after the slow start and now the change has been made with Oldham sitting third from bottom of the National League table.
A statement this morning confirmed: “Following 12 months in his position as first-team manager, Oldham Athletic can confirm it has parted company with David Unsworth.
“After a strong finish to the 2022/2023 season, a sizeable investment in the playing budget and some highly promising signings during the summer, the start of the current campaign has unfortunately not met the expectations of the club.
“Following the takeover of Oldham Athletic by the Rothwell family in July 2022, it has been one of their main principles to stay out of the day-to-day running of football activities within the business and provide stability for the long-term survival of the club.
“David signed for three seasons, to bring stability on the playing front, but despite the hard work and dedication of David and his coaching team, results have not worked out on the pitch.
The board wishes David and his assistant, John Ebbrell, all the best for the future as they pursue their careers in club management. Unfortunately, on this occasion, it has not worked out as well as we all expected.”