The Banshees of Inishern, which had been nominated in nine categories, missed out last night.
Richard Baneham won his second visual effects Oscar for his work on Avatar: The Way of Water.
The Tallaght man began his acceptance speech by saying: "Go raibh maith agat."
Northern Irish comedy-drama An Irish Goodbye won Best Live Action Short Film.
An Irish Goodbye's writer-directors, Tom Berkeley and Ross White, were joined onstage by stars James Martin and Séamus O'Hara as they accepted their Oscar.
The Banshees of Inishern, which had been nominated in nine categories, missed out last night as Everything Everywhere All at Once took home seven Oscars.
Irish film An Cailín Ciúin went home empty-handed as All Quiet on the Western Front took home the award for Best International Feature Film.
The Whale's Brendan Fraser took home the Oscar for Best Actor - the category which included Maynooth's Paul Mescal and Colin Farrell.

Analysis: Damning Reports Detail Rot, Fire Risks And Rodents At "Temporary" Celbridge Primary School
Kfm Obituary Notices
Major Curragh Community College Project Moves Ahead After Years Of False Starts
Plans For Walking Trail Within Castletown House Lands Under Consideration Subject To Removal Of Laurel
Council Blames Stolen Cars As It Refuses Warning Signs At Crash-Prone Bridge In Celbridge
Naas No-Shows Add To Driving Test Pressure As Kildare Test Queue Hits 1,975
Naas Hospital Promised Just 21 Extra Mental Health Beds At Lakeview Ward - With No Timeline In Sight
R405 Hazelhatch Road To Close Between Loughtown Road And Athgoe Road For Major Pipeline Works