Head coach Philippe Aw has been relieved of his duties with immediate effect. Assistant coach Clement Teo has been installed as caretaker coach.
Hougang endured their worst-ever start to a Singapore Premier League season and are still without a win after 10 matches.
The club put out a statement on Sunday evening with the announcement as the league takes a six-day break before resuming next Sunday.
Aw took charge at Hougang in 2017 after spending three years at Home United where he made a name for himself as a tactician who shaped his team to play a passing game on the ground.
It remains to be seen who will be brought in but ex-Woodlands Wellington coach Salim Moin has been spotted at the last few Hougang matches.