Timothée Chalamet and Saoirse Ronan may both have two films each vying for awards contention this year in Chalamet’s “A Complete Unknown” and “Dune: Part Two” and Ronan’s “The Outrun” and “Blitz,” but the pair took the time to reunite in London to discuss two films they appeared in together at the earlier stages of their careers.

In a special event hosted by the British Film Institute and Vanity Fair at the BFI Southbank on Wednesday evening, Chalamet and Ronan reflected on making 2017’s “Lady Bird” and 2019’s “Little Women,” both from a pre-“Barbie” writer/director Greta Gerwig.

While the two hadn’t me prior to “Lady Bird,” Chalamet recalled being told about Ronan by Emery Cohen, who had worked with her on the 2016 hit “Brooklyn.”

“I kept hearing this name ‘Saoirse, Saoirse’ and didn’t put two and two together when I saw the name spelled out,...