The 3-0 defeat at Fulham on Saturday, Wolves' eighth league loss, left the club bottom of the table and eight points from safety. Supporters turned on Pereira during and after the match, with chants calling for his dismissal.
Pereira, 57, was appointed in December 2024 and guided Wolves to 16th place last season, comfortably avoiding relegation. He signed a new three-year deal in September, but the team's form deteriorated, and a run of poor results made his position untenable.
All eight members of his coaching staff have also left. Under-21 manager James Collins and Under-18 boss Richard Walker will oversee training while a new head coach is sought.
Executive chairman Jeff Shi said the club was grateful for Pereira's work last season but admitted the start to the new campaign had been "a disappointment."
Wolves were knocked out of the Carabao Cup by Chelsea in midweek and remain the only winless side across England's top four divisions. Pereira's departure means the club will now be searching for their fifth permanent manager in four years.
"Upon his arrival at Molineux last December, Pereira and his coaches made an immediate impact, guiding the team to a successful second half of the Premier League campaign," Wolves said in a statement.
"However, results and performances this term have fallen below acceptable standards, and as a result a change in leadership was deemed necessary.
"All eight of Pereira's backroom staff have also left the club."