• Arsenal in a statement on Friday said the decision had been "taken due to results and performances not being at the level required".
• Statement: “Our most sincere thanks go to Unai and his colleagues who were unrelenting in their efforts to get the club back to competing at the level we all expect and demand."
Unai Emery has been sacked as Arsenal manager after 18 months in charge.
The Spaniard, who previously led Paris St-Germain to the French league title and won three Europa Leagues with Sevilla, was appointed Gunners boss in May 2018, succeeding Arsene Wenger.
Arsenal in a statement on Friday said the decision had been "taken due to results and performances not being at the level required".
Speaking on behalf of the Arsenal board and our owners Kroenke Sports & Entertainment, Josh Kroenke said: “Our most sincere thanks go to Unai and his colleagues who were unrelenting in their efforts to get the club back to competing at the level we all expect and demand. We wish Unai and his team nothing but future success.”
He is to be replaced on a temporary basis by the assistant and former Arsenal midfielder Freddie Ljungberg.
"We have asked Freddie Ljungberg to take responsibility for the first team as interim head coach. We have full confidence in Freddie to take us forward. The search for a new head coach is underway and we will make a further announcement when that process is complete," the statement read.
The Gunners have not won in seven games and lost 2-1 at home to Eintracht Frankfurt in the Europa League on Thursday.
It is their worst competitive run without a victory since February 1992, which was eight games under George Graham.
They are without a Premier League victory since 6 October and eight points off the top four.
The Arsenal Supporters' Trust (AST) said Emery's dismissal was "unfortunate but inevitable" and the "more difficult challenge is to recruit a suitable successor".
It added: "We are far from certain that Arsenal has the right personnel to lead this process.
"The AST has long been advocating that the most important changes needed at Arsenal are in the boardroom where Arsenal need better governance."
Arsenal finished fifth in 48-year-old Emery's first season in charge at Emirates Stadium after he replaced Wenger.
They went into this season having spent more than £130m in the summer after signing winger Nicolas Pepe, centre-back David Luiz, left-back Kieran Tierney, striker Gabriel Martinelli and defender William Saliba, who will join next summer.