Is the Cato Club based on a real London club?

Externally, the Cato Club is modeled on London’s Institute of Directors (pictured)—part traditional club, part professional association—located on Pall Mall across from Waterloo Place and the Crimean War Memorial where Evans waited for the florist to appear. The interior is based loosely on the East India Club.

As for the Cato Club’s male-only membership policies, several of the traditional London clubs, including the East India Club, still do not accept female members. As far as is known, none of their Rules Committees has ever used the Cato Club’s subterfuge of designating a woman as an “honorary man” to admit her to membership.