- First time two black nominees won Best Supporting awards in the same ceremony; in general, first time an Oscar ceremony featured more than 3 black winners
- First time in almost twenty years that all acting winners are American
- First time in 10 years that the Best Actor nominee who won the SAG did not win the Oscar (Washington/Affleck)
- First time a Muslim actor won an Oscar (Ali)
- First time in almost 20 years that all acting awards went to people playing fictional people
- First time a movie with 14 nominations failed to win Best Picture
- First time a Potter movie won an Academy Award
- First time a DC Universe movie won an Academy Award
- First time a living person was included in the "In Memoriam" Segment
- First time Kevin O'Connell won an Oscar after 21 nominations (Hacksaw Ridge, Sound Mixing)
- First time the wrong Best Picture winner was announced
- First time Netflix (White Helmets) and Amazon (Manchester By the Sea) films won Oscars
Other random trivia:
- Natalie Portman is the first absentee acting nominee since Judy Dench (2014)
- Ryan Gosling joins Jonah Hill and Eddie Redmayne as the only male actors born after 1980 to be nominated for acting awards more than once
- This year was the first time in 9 years that an American male won Best Director
- This year's ceremony is the longest running one in 10 years (3 hours 50 minutes)
- Damien Chazelle is the youngest person to win Best Director
- OJ Made in America is the longest film to win an Oscar (7 hours, 47 minutes)
- Iran is the fourth country to win 2 Oscars after Argentina, Austria and Japan (which has won 4).
- No Best Picture winner in the past 10 years has featured an actress nominated in the lead role
[Source]