Manuel Pellegrini was sacked by West Ham after the 2-1 home defeat by Leicester on Saturday.
Here, the PA news agency looks at five possible contenders to replace the 66-year-old.
Benitez, currently in charge of Chinese Super League side Dalian Yifang, has made no secret of his desire to return to the Premier League. His departure from Newcastle at the end of his contract in June was met with disdain by the Toon Army and the Spaniard could be tempted into a swift return to the UK as his family are still based in the north west. The 59-year-old, who has also had spells in charge of Liverpool, Inter Milan, Chelsea and Real Madrid, signed a reported two-and-a-half-year deal with Dalian Yifang in July.
Howe is another contender after guiding Bournemouth to the Premier League for the first time in 2015 and keeping them there with 16th, ninth, 12th and 14th-placed finishes. Two hugely successful spells in charge of the Cherries have sandwiched two seasons as boss at Burnley, who he left in 2012 for personal reasons. He appears destined for the dugout at one of English football’s traditional big clubs and would be a popular choice at West Ham, but whether they could entice him away from the south coast is another matter.
The 56-year-old Scot has appeared high on the bookmakers’ list for a return to West Ham, who he steered to Premier League safety after signing a short-term deal with the club until to the end of the 2017/18 season. The former Everton and Manchester United boss took charge when the Hammers were in the bottom three and after leading them to a 13th-placed finish hinted he wanted to stay beyond his six-month contract. But despite achieving what he had been hired to do, Moyes never appeared likely to be long-term manager.
Bowyer has been quick to make an impression in his first job as a manager at Charlton, who he led to promotion to the Sky Bet Championship via the play-offs in May in his first full season in charge. The Addicks have dropped out of the play-off places after a flying start in the second tier and the 42-year-old would represent a big gamble by the West Ham hierarchy. But the former Leeds midfielder, whose short spell as a Hammers player was hindered by injury, would be a popular choice according to fans on social media.
Hughton has been out of work since May when he was sacked by Brighton following a poor run of three wins in 23 Premier League games. However, the 60-year-old, who played 32 games for the Hammers between 1990 and 1992, had led the Seagulls to the Premier League for the first time in their history in 2016-17 and a 15th place finish in their first season back in the top flight. Hughton also won promotion to the Premier League with Newcastle in 2009-10 when they were unbeaten at home during the entire campaign.