[6][7] On 18 August, West Ham began their European campaign by playing Danish team Viborg in the first leg of the 2022–23 UEFA Europa Conference League play-off round.

Manager David Moyes, captain Declan Rice and defender Aaron Cresswell were all suspended following disciplinary incidents against Eintracht Frankfurt in the previous season's Europa League semi-final.

[8] Two of Viborg's players, Nigerian winger Ibrahim Said and Gambian forward Alassana Jatta were unavailable as the club was unable to gain entry visas to the UK following new rules applicable to non-EU nationals following Brexit.

[11] New signing Thilo Kehrer made his league debut in the match, fouling Danny Welbeck in the box and giving away a penalty, which Alexis Mac Allister converted.

Kai Havertz scored the winning goal in the 88th minute, however, a last-minute West Ham equaliser from Maxwel Cornet was controversially disallowed by referee Andy Madley after a VAR check deemed that Chelsea goalkeeper Édouard Mendy had been fouled by Jarrod Bowen.

The Hammers won the game 3–1, after suffering a first-half setback from FCSB's Andrei Cordea, goals from Jarrod Bowen, Emerson and Michail Antonio sealed the win to put West Ham top of Group B after the first round of matches.

[23] Players from both teams wore black armbands and a minute's silence was held before kick-off, fans also sung a rendition of the United Kingdom's national anthem "God Save the Queen" in tribute to the late monarch.

[31][32] The Hammers officially sealed their place in the Conference League knockout stages on 13 October with a 2–1 win over Anderlecht, Saïd Benrahma and Jarrod Bowen scored in the first half before Sebastiano Esposito pulled one back for the Belgians via a penalty in the 89th minute.

[40] The game was summer signing Nayef Aguerd's competitive debut, as he had just recovered from an ankle injury he sustained in a pre-season friendly against Rangers in July.

Several Academy players made their senior competitive debuts in the match, including Mubama, Oliver Scarles, Kamarai Simon-Swyer and Kaelan Casey.

They lost the game 2–1, with Saïd Benrahma putting the Hammers ahead early before Wilfried Zaha equalised for the Eagles late in the first half, Michael Olise then scored an added-time winner for Palace.

Despite many attempts from Lucas Paquetá, Declan Rice, Saïd Benrahma and Gianluca Scamacca, the game remained 1–0 until Harvey Barnes made it two for Leicester late on.

[57] Five West Ham players were called up for the World Cup by their respective national teams: Declan Rice for England, Alphonse Areola for France, Thilo Kehrer for Germany, Nayef Aguerd for Morocco and Lucas Paquetá for Brazil.

The Gunners fought back in the second half and won the match 3–1, with goals from Bukayo Saka, Gabriel Martinelli and Eddie Nketiah sealing the comeback victory.

[64] A minute of applause was held before the match to honour Brazilian footballer Pelé, who had died the day before, players from both teams also wore black armbands in tribute.

Gianluca Scamacca put the Hammers ahead early in the second half before Rodrigo scored for Leeds in the 70th minute to level the match, which ended in a 2–2 draw.

[68][69] The tributes included a bouquet of flowers being left at his allocated seat in the director's box, a round of applause from fans of both teams and black armbands being worn by all players on the pitch.

The Hammers won the match 1–0 after a late Saïd Benrahma goal, ending their six-game winless run and progressing to the fourth round,[71][72] where they were drawn away to Derby County.

The Hammers won the match 2–0, with Jarrod Bowen scoring both goals in the first half, ending their seven-game winless run and taking the club out of the relegation zone.

The Hammers won the match 2–0, with goals from Jarrod Bowen and Michail Antonio sealing the win to send West Ham through to the fifth round, where they were drawn away to Manchester United.

[87] When asked about the match and West Ham's overall situation in post-match interviews, manager David Moyes expressed disappointment at the defensive errors which led up to Emerson Royal's opener, whilst midfielder Flynn Downes said, "we know what we are in for now - it's a relegation battle".

[94][95] During the second half, manager David Moyes was the target of chants such as "you don't know what you're doing" and "sacked in the morning" whilst captain Declan Rice described the match as "demoralising" and apologised to supporters in a post-match interview.

[102][103][104] The Hammers did not play during the final week of the Premier League before the March international break as their away match against Manchester City was postponed due to the Cityzens progressing into the quarter-finals of the FA Cup.

[105][106] During the March international break, seven West Ham players were called up to participate in UEFA Euro 2024 qualifying: Declan Rice for England, Alphonse Areola for France, Vladimír Coufal and Tomáš Souček for the Czech Republic, Gianluca Scamacca and Emerson Palmieri for Italy and Thilo Kehrer for Germany.

[107][108] On 2 April, West Ham beat fellow relegation strugglers Southampton 1–0 in a Premier League game thanks to a goal from Nayef Aguerd, his first for the club.

[120][121] West Ham played the second leg of the quarter-finals of the Europa Conference League against Gent at the London Stadium on 20 April winning 4–1, resulting in an aggregate score of 5–2 and earning a place in the semi-finals against AZ Alkmaar.

They added three goals in the second half through a Lucas Paquetá penalty awarded after a handball by Joseph Okumu, a third by Declan Rice described as "brilliant" and a second for Michail Antonio in the 63rd minute.

With eyes on the upcoming Europa Conference League semi-finals second leg on 18 May, David Moyes made seven changes from the team which had beaten Manchester United the previous week.

The game remained goalless until referee Carlos del Cerro Grande awarded the Hammers a penalty in the second half after the ball hit the hand of Fiorentina captain Cristiano Biraghi after a long throw into the box.

[205] During the 2022 FIFA World Cup, West Ham travelled to Cambridge United for the testimonial of Greg Taylor, then to Italy to play Udinese and finally to Fulham for winter-break friendlies.