The crystal microphone the group were awarded was sold in a Facebook auction led by Ukrainian TV presenter Serhiy Prytula on Sunday.
The money will be used to buy drones for the Ukrainian armed forces fighting invading Russia troops.
The winning bid for the trophy was attributed to Whitebit, a cryptocurrency exchange, and came in the form of 500 Ethereum.
Writing on Facebook, the band said: “You guys are amazing!
“We appreciate each and every one of you who donated to this auction and a special thanks to the team Whitebit who purchased the trophy for $900,000 and are now the rightful owners of our trophy.”
Ukraine swept the public vote at Eurovision to claim an emotional win with their entry Stefania, riding a wave of public support amid Russia's invasion of Ukraine.
Mr Prytula said there were 31,088 entries into the hat raffle, and that the winner was in the Czech Republic.
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Kalush Orchestra, who were fighting as part of the Ukrainian resistance only weeks before Eurovision, received support from across Europe for their performance.
On their return to Ukraine, they were met by a crowd of supporters near the Polish border who were rewarded with an impromptu performance from the group.
The band were given special permission to leave Ukraine for the competition - most Ukrainian men between 18 and 60 are barred from leaving in case they are needed to fight.
The money raised from Sunday's auction will be used to buy the PD-2 unmanned aerial system, which includes three aircraft and a ground control station, Prytula said at the auction as the war in Ukraine enters its third month.
The UK's Eurovision star, Sam Ryder, who came second in the contest, told ITV News he would love to work with Kalush Orchestra, claiming it was "only a matter of time".