Book 1984 written in 1948 actually. Then also on book Brave New World by Aldous Huxley. Also by Fahrenheit 451 by Ray Bradbury. The Giver is also to a much lesser extent.
Movies it could have gotten inspiration from Logan's Run, and THX 1138.
Real world events it clearly alludes to are both , Soviet Russia under Lenin and Stalin, as well as Hitler's Germany. Both of these countries were ran by similar fascist ideologies. You also see clear architecture and interiors that clearly resemble both, Hitler's German architecture, the Soviet architecture, and even interior where the Father sat looks almost same as Stalin's headquarters cabinet.
I still have problems with this movie which how it suggests that the modern antidepressant's and anti anxiety drugs we take are bad. Nothing could be further from the truth.

Equilibrium entire setup is 1984.

say it isn't so!!

The giver is based off a book from the 90s. So if anything this movie ripped off "the giver".