Amongst those who weren't named was Beverly Hills 90210 and Riverdale star Luke Perry, who died last year at the age of 52.
It seemed especially jarring given that he was part of one of the year's most celebrated films, Once Upon a Time in Hollywood.
Cameron Boyce was also absent from the video and photo montage. The actor died at the age of 20 in July.
Furthermore, horror icon Sid Haig was also left off the list of honorees. He died in September at age 80.
Naturally, Twitter took note of these gaping holes in the tribute. See some of the reaction below.
Amongst the names that were included in the "In Memoriam" segment were Kobe Bryant, Peter Mayhew, John Singleton and Kirk Douglas.
imagine your last role being nominated for best picture and the academy still overlooks you. #LukePerry deserves so much better.— lilya🦋 (@oddscissors) February 10, 2020
Sid Haig was an absolute legend. A wonderful actor and a beautiful human being.— Horror Seen (@HorrorSeen) February 10, 2020
For him to be blatantly ignored by 'The Academy' for their In Memoriam section is an absolute disgrace .
And this also goes to Luke Perry and Cameron Boyce . pic.twitter.com/WfgYHkT4lM
The In Memoriam segment at the #Oscars did not include Luke Perry, Cameron Boyce or Sid Haig.— Natasha Del Riego (@natashaaa__) February 10, 2020
Who is in charge of putting the tribute together? Literally one google search and several sites have put together a list with all those who have passed recently. pic.twitter.com/0Kv8yOZ89G
Sadly there's always someone who gets overlooked in the Oscar's memoriam but geez, Luke Perry? He was actually in Once Upon A Time In Hollywood for fuck sake.#LukePerry— WhatserName (@IamEveryDayPpl) February 10, 2020