After a disappointing start, David Moyes' side recorded their first win of the season against Wolverhampton Wanderers last time out and will be wanting to continue that form this weekend.
The Foxes, meanwhile, are coming into the game off the back of a stunning 5-2 away victory against Manchester City.
Ahead of the fixture on Filbert Way, LCFC.com takes a detailed look at the Hammers...
The squad
West Ham have a number of long-serving players including Mark Noble, who has made over 400 appearances for his boyhood side since making his professional debut in 2004.
They also have a wealth of internationals in attack, including Brazil international Felipe Anderson, Ukraine’s Andriy Yarmolenko and Argentina forward Manuel Lanzini.
Winger Jarrod Bowen, meanwhile, who signed from Hull City in January 2020, has started the season off in fine form, netting twice in the victory over Wolverhampton Wanderers.
In defence, left-back Aaron Cresswell and Italy defender Angelo Ogbonna provide experience, alongside the likes of Fabián Balbuena and Issa Diop.
This summer, West Ham made Tomáš Souček's loan move a permanent one, securing the Czech Republic international for a reported fee of £14.5M after the midfielder made 13 appearances during the second half of last season, scoring three goals.
There were several departures, including goalkeeper Roberto heading to La Liga outfit Alaves and winger Grady Diangana moving across to newly promoted West Bromwich Albion.
Also leaving London Stadium for transfer fees were forwards Albian Ajeti, to Celtic, and Jordan Hugill, to Norwich City.
Pablo Zabaleta and Carlos Sanchez were released at the end of their contracts, competing the departures from David Moyes' squad.
The manager
Former Preston North End, Everton, Manchester United, Real Sociedad and Sunderland manager David Moyes returned to West Ham for a second spell in charge at the end of 2019.
After Manuel Pellegrini left the Hammers, following a 2-1 home defeat by Leicester, the Scottish manager signed an 18-month contract at London Stadium.
His first game back in the capital was a 4-0 success over Bournemouth, before another 4-0 win, at Gillingham, in the Emirates FA Cup.
Moyes is an experienced manager who has worked at the game's pinnacle, taking the Manchester United post after 11 successful years at Goodison Park.
He arrived in Merseyside having guided Preston to promotion from the Third Division and settling in the second tier, before sealing Everton a UEFA Champions League qualifying spot in 2004/05.
The Toffees fell in the qualification stages, but finished in the top half for the rest of Moyes' tenure, as well as being beaten FA Cup finalists in 2009, before replacing Sir Alex Ferguson at Old Trafford.
However, Moyes' time at United, which included a Community Shield success, was cut short by disappointing domestic form and the Glasgow-born former defender left the Red Devils in April 2014.
His next move was to Spain to manage La Liga club Real Sociedad in November 2014 and, while form initially improved, Moyes was dismissed a year after taking the post.
Moyes' next job was to replace Sam Allardyce at Sunderland, but his only season in charge at Stadium of Light ended with his first career relegation, as the Black Cats fell into the Championship.
Later that year, his first spell at West Ham began in November, with Moyes inspiring the east London outfit to climb out of the relegation zone and towards safety in the 2017/18 campaign.
Despite leaving at the end of that season, West Ham returned to Moyes in late December 2019, to replace Pellegrini as the Hammers aimed to move away from the bottom three.
They finished the 2019/20 season in 16th position, on 39 points, five points clear of the relegation zone.
Form guide
West Ham have endured a mixed start to the new season, losing 2-0 at home to Newcastle United on matchday one, before an away defeat to Arsenal a week later.
A 4-0 victory over Wolverhampton Wanderers last time out has moved the Hammers up to 11th in the early standings. A brace from Jarrod Bowen and Sébastien Haller's late goal settled the game, either side of Raúl Jiménez's own goal.
The Londoners have also progressed in the Carabao Cup, dispatching Sky Bet League One sides Charlton Athletic and Hull City to set up a fourth round tie with Everton.
Previous encounters
Of the 134 competitive games between the two sides, Leicester have come out on top 49 times, with West Ham edging the total number of victories (52).
There have been 33 draws, including the first meeting, a Second Division clash back in November 1919, which finished 0-0.
More recently, the Foxes have had the upper hand, winning both Premier League matches last season.
Leicester triumphed 2-1 at London Stadium in December 2019, before also putting their opponents to the sword in the reverse fixture a month later, with a 4-1 win over the East London side.
In fact, City are unbeaten in their last four meetings with the Hammers and have lost just one of the last 12 games between the pair.
Trophy cabinet
West Ham United have enjoyed success on both the domestic and European front since their formation in 1895.
They have won the FA Cup in 1964, 1975 and 1980, they lifted the Charity Shield (now Community Shield) in 1964 and have won England’s second division on two occasions – in 1958 and 1981.
In 1999, the Hammers won the UEFA Intertoto Cup alongside Juventus and Montpellier, while in 1965, they claimed the European Cup Winners' Cup with a 2-0 success over 1860 Munich.
In front of over 97,000 fans at Wembley Stadium, the late Alan Sealey scored twice in three second-half minutes to win it for his side.
The stadium
West Ham United moved to the London Stadium in 2016, having previously played at Upton Park for over a century.
The 60,000-seater stadium was originally constructed for the 2012 Summer Olympics, serving as a track and field venue.
In addition to athletics and football, the London Stadium has also hosted baseball and rugby league matches, as well as motorsport’s 2015 Race of Champions.
Upcoming fixtures
After travelling to King Power Stadium, West Ham are on the road again, facing London rivals Tottenham Hotspur away on Saturday 17 October (3pm kick-off).
Fixtures against Manchester City (H) and Liverpool (A) complete the Hammers' October schedule.
West Ham are set to finish the season with home games against Everton and Southampton, either side of trips to Brighton and Hove Albion and West Bromwich Albion.