Located adjacent to London Waterloo railway station, in central London's South Bank, the club has over 260 rooms for accommodation (singles, twins, doubles, fully accessible, family, suite and flats), restaurant, bar, small library, and a full range of meeting and banqueting rooms which can be hired by the public.
The idea for the club came from Ethel McCaul, a Royal Red Cross nurse who served in field hospitals during the South African War at the start of the 20th century.
She noted that while officers enjoyed membership of various gentlemen's clubs in London, no equivalent existed for enlisted personnel and they therefore used public houses and inns of varying repute.
For many years after the First World War an annual donation was sent anonymously to the Union Jack Club and with each payment came a note with the words “In gratitude for a scrap of comfort”.
During the Second World War, the area around Waterloo Station was bombed severely and the Union Jack Club itself suffered considerable damage which required extensive repair.
In 2004, Queen Elizabeth II and her husband Prince Philip, Duke of Edinburgh visited the club to help celebrate its centenary.