The channel was due to show the awards between 4 a.m. and 9 a.m. Moscow time on Monday, AFP reported Sunday.
In a statement, Channel One said: "Due to the large amount of news concerning the situation in Crimea and Ukraine, and the audience's rising interest in news programs, Channel One considers it impossible to air the Oscars ceremony for five hours, particularly in the morning."
It added that the awards would be aired at midnight on Monday instead.
Yury Gladilshchikov, a film critic for Moskovskiye Novosti newspaper, who had been invited to be a commentator for the Oscar ceremony, said he was told late Sunday that live coverage had been cancelled.
"They are gathering politicians for the morning programming," Gladilshchikov said on Facebook.
Russian media has demonstrated unwavering support for Vladimir Putin's intervention in Ukraine.
"Our propaganda on state channels is really running wild," commented former economy minister Andrei Nechayev on Twitter.
Channel One is 51% owned by the state, and 49% by private shareholders. The Russian broadcasting scene is dominated by channels that are either run directly by the Kremlin or owned by companies with close links to the government, such as Gazprom.
western media outlets do the same.