The Maynooth native looked suave in a custom Gucci look which featured a white satin double-breasted blazer with a red rose corsage and black trousers, while Dearbhla looked elegant in a sleek black gown with gold fern embellishment across one shoulder.
The 27-year-old, who rose to fame on Normal People, was up against fellow Irish actor Colin Farrell in the same category but ultimately both lost out to Brendan Fraser, who won for his turn in The Whale.
Mescal’s Oscar nomination was a bittersweet moment for him and his family as news broke of his nod ahead of his mum beginning treatment for multiple myeloma, a type of bone marrow cancer.
At the time, his sister, musician Nell Mescal, shared a picture of their family’s reaction to his career feat on a group video call, captioning it with a crying emoji, before revealing their mother was about to start chemotherapy.
She shared on Twitter last month: “My mum got a haircut today in prep for her chemotherapy and then Paul got nominated for an Oscar life is so crazy.”
Dearbhla previously shared on Instagram that she was diagnosed with the disease last July and has documented her treatment journey on social media since.
Elsewhere, Michelle Yeoh made history at the 95th Oscars as Everything Everywhere All At Once took home a clutch of major awards.
The multiverse sci-fi epic, directed by Daniel Kwan and Daniel Scheinert, claimed seven prizes including three acting gongs, best directing and best picture, the biggest of the night.
It was a disappointing evening for Irish talent with The Banshees Of Inisherin going home empty-handed despite its nine nominations.
Academy Awards | Oscars 2023 | Red Carpet
Yeoh claimed the Oscar for best leading actress, fending off competition from two-time Oscar winner Cate Blanchett to become the first woman from an Asian background to win the prize.
Taking to the stage, she said: “For all the little boys and girls who look like me, this is a beacon of hope and possibilities.
“Dream big, dreams do come true. Ladies, never let anyone tell you you are past your prime.”
She added: “This is history in the making.”