The club was established in 1831 and has always been exclusively for men.
However, according to UK media, a decision to allow female members was approved by nearly 60% during a secret meeting.
According to reports, actors Stephen Fry and James Naughtie, a journalist, were two of the speakers who spoke in favor of admitting women.
The King, Oliver Dowden, the Deputy Prime Minister, and Sir Richard Moore, the head of MI6, were all allegedly members of the club, according to a prior report by The Guardian that purported to be its membership list.
The head of the civil service, Cabinet Secretary Simon Case, left the club in it.