She arrived "fashionably late", according to her partner, rapper A$AP Rocky.
Singer Rihanna stuns with baby bump at Met Gala, third pregnancy confirmed
But when she did, Rihanna turned heads and cameras on the carpet immediately.
Aside from her outfit, featuring pinstripes and an enormous black hat - in accordance with this year's Met Gala theme honouring the fashion movement of black dandyism - the singer attracted the attention with a considerably sized baby bump.
Earlier in the day, her partner A$AP Rocky confirmed to reporters that the couple were indeed expecting their third child.
The two artists are already parents to two little boys, born in 2022 and 2023.
It was not the first time that Rihanna chose to announce a pregnancy during a major event: in 2023, she debuted her second pregnancy during her half-time performance at the Super Bowl.
This year's Met Gala, which celebrates the Costume Institute’s new exhibition Superfine: Tailoring Black Style, which is on show from 10 May onwards, was co-chaired by her partner A$AP Rocky.
His particular role in this year's edition comes after several years of the rapper and Rihanna making regular appearances at the gala, often closing down the carpet with their carefully-chosen outfits.