Elizabeth, 23, was up for the EE Rising Star of the Year honor, which went to Juno Temple.
After the star-studded ceremony, Elizabeth was seen at the official after party held at the Grosvenor House Hotel.
Just the night before, Saoirse was seen at the 2013 IFTA Awards.
FYI: Elizabeth dolled up in head-to-toe Chanel. Saoirse wore a Christopher Kane dress.
15+ pics inside of Saoirse and Elizabeth…