Keira Knightley & Clive Owen Celebrate Roundabout's 50th Anniversary!

Keira Knightley keeps it chic and sophisticated while arriving at Roundabout’s 50th Anniversary Season Party held at the Roundabout Theatre Company on Thursday (September 10) in New York City.

The 30-year-old actress was joined at the event by Clive Owen and his Old Times co-star Kelly Reilly, Mamie Gummer, Blythe Danner, and Keira‘s Thérèse Raquin co-stars Judith Light, Gabriel Ebert, Matt Ryan and director Evan Cabnet.

PHOTOS: Check out the latest pics of Keira Knightley

Thérèse Raquin is a tale of love, lust, betrayal and guilt, Thérèse (Knightley) and her lover Laurent set off on a violent path that may have far worse consequences for the perpetrators than for the victims – Previews begin on October 1st!

20+ pictures inside of Keira Knightley, Clive Owen and others at the event…