The striking Theatre building, situated in the heart of the College, was formerly part of the University Museum of Classical Archaeology. The Theatre retains much of its original character as a Victorian lecture room, with continuous upholstered bench seating in two tiers across a curving auditorium, a raised stage and gallery.

Fully refurbished in 2005, the Theatre seats 180 people along with air-conditioning. Peterhouse offer a range of uses for the Theatre, from simple talks to fully livestreamed events. The theatre has recently been fitted with pan tilt zoom cameras that can record or stream an event at high quality, industry grade Martin surround sound audio and sennheiser radio microphones to allow for portable and interactive lectures and showcases. 

The adjacent Lubbock Room and foyer provides the ideal location for refreshments, break-out groups and smaller gatherings.