The Hammers were defeated 5-0 by Chelsea at the weekend, the second consecutive Premier League away game in which they have conceded five goals.
They had also lost four of their last eight league matches, and won just one of the others, as Moyes struggled to keep the club’s season alive.
West Ham are currently in ninth place, five points behind Manchester United, who have two games in hand, meaning there is little chance of European football next season.
“I have enjoyed four and a half brilliant years at West Ham, and the club is in a stronger position than when I returned back in 2019,” Moyes said in a statement.
“When I joined West Ham for a second time, the club was one place above the relegation zone, and it has been a terrific journey to have achieved three consecutive seasons in Europe.
“After leading the club to safety, we guided the team to finishes of 6th and 7th in the Premier League, and I was delighted when we won the Europa Conference League title last June – the club’s first major trophy in 43 years.
“I would like to thank all the players for their support, and all the success they have achieved, over the last four and a half years. I have really enjoyed working with everyone at West Ham, and I would like to thank the board for giving me the opportunity to manage this great club.”
Pressure had been building on the former Everton manager this campaign as fans’ ambitions were raised by the success of the previous campaign.
