West Ham know their opponents for their first European campaign in 15 years after the Europa League group stage draw was made.
The Hammers lost in Europa League qualifying in 2015/16 and 2016/17, but have not been in a main competition since the 2006/07 UEFA Cup, where they went out in the first round.
David Moyes’ men have been drawn against Dinamo Zagreb, Genk and Rapid Vienna in Group H.
Their toughest test will likely be Zagreb, who beat Tottenham in last season’s round of 16.
Leicester, who missed out on Champions League qualification on the final day of last season, are back in the Europa League for the second year running, having been knocked out in the last 32 in 2020/21.
The Foxes face Napoli, Spartak Moscow and Legia Warsaw in Group C.
Rangers are back in this competition after failing to make it through the Champions League qualifiers.
They were controversially beaten by Slavia Prague last season and they will return to the Czech Republic capital, having been drawn in Group A against Lyon, Sparta Prague and Brondby.
Celtic are in Group G with Bayer Leverkusen, Real Betis and Ferencvaros.
The group stage kicks off on September 16, with the schedule due in the next 24 hours, with the final set to be at the Estadio Ramón Sánchez-Pizjuán in Sevilla.
UEFA is reviewing whether away fans will be able to travel, with qualifying fixtures across all three club competitions watched by home fans only.