Orwell's works are in the public domain in Canada, Australia and Russia (and all life+50 countries in 2001, Orwell died in 1950). See
The Illegal Link: Orwell’s Copyright Police State - Reloaded.
They are still in copyright in the US and most of Europe. The copyright owners are aggressive about asserting their rights (even when they probably don't have any). See
1984 copyright holders threaten over anti-Hillary Clinton ad.