There were concerns the centre-back could be left out Roberto Martinez's final group for Russian Federation, with FIFA having imposed a deadline of June 4 for every competing team to finalise their squad.
Kompany is joined by Kevin De Bruyne, which should surprise no one, while Manchester City academy graduate Dedryck Boyata, who replaced Kompany against Portugal, also gets to experience the World Cup.
Laurent Ciman will be with the Belgium squad and is on stand-by should Kompany fail to recover in time.
Federation Internationale de Football Association required all nations to confirm their squads for the tournament by Monday, 4 June, and former Everton manager Roberto Martinez has now made his final decision.
U.S. risks sparking global trade war
Throughout these talks, the US has sought to use the threat of trade restrictions as leverage to obtain concessions from the EU. May says Britain and the European Union "will continue to work together to protect and safeguard our workers and industries".
"Vincent Kompany is a true leader". He said: "Until 24 hours before [the first match] we can still make a replacement. His fresh performance and leadership means it is essential for us to give him time to make a good decision".
Newcastle goalkeeper Matz Sels, Watford's Christian Kabasele and fellow defender Jordan Lukaku of Lazio are the other players to miss out, while Los Angeles FC defender Laurent Ciman is on standby.
"We have two number nines - Michy Batshuayi and Romelu Lukaku have taken those positions".
Belgium face Panama in their opening Group G match in Sochi before taking on Tunisia and England.
Last week, footage of 23 mattresses being loaded up by a Belgian bedding company before their departure for Russian Federation had people guessing who would miss out on a place.