The Liar's Club is a social organization that engages in camaraderie and charitable events for professional men of middle-class and higher means. The premise of the Liar's Club was that members had to tell the best tall tales and fables and to one-up each other on the most outrageous fictions.  The Liar's Club frequently had events for the members to tell the Biggest Lie with proceeds for the evening going to charitable causes or the War effort.

The exact beginnings of the Liar's Club on Earth-Two are not precisely known.  It is know that by the 1940's, there were branches in all over the United States.  The earliest recorded case was when Ted Knight was inducted into the Gotham Liar's Club through his friend, banker Cliff Henry.  Ted Knight announced the assembled Liars that he was in reality Starman, which was greeted with gales of laughter that the foppish Knight could be the Astral Avenger,  Another member, Russell Vardon, was later revealed to be The Veil, a criminal hypnotists who attempted his fellow members of the bank board of directors to cover his thefts of bank funds (Adventure Comics #75).

The best known of the Liar's Club was found in Keystone City. By 1943, Jar Garrick was known to be a regular member of this club, often regaling them with actual adventures that the Flash had experienced but that members of the club were convinced were lies.  In his first time winning the Biggest Whipper Award, Garrick shared how the Flash was testing his own speed and accidentally ran 500 years into the future, ending up saving the planet from solar instability while he was there. When he tried to deny his prize and claim the story was true, he was treated to a ceremonial dunking (Flash Comics #44).  Garrick remained a member in good standing of the Keystone Club at least through 1947 (All-Flash#30).

A branch of the Liar's Club also existed in Metropolis at least as early as 1944.  That year Liar's Club member Arthur Boyle spun a fantastic yarn in which the labors of Hercules were actually done by the Man of Steel, though there is no evidence this was anything more than a fiction of Boyle's (Superman #28).  The Metropolis Club also had a youth chapter, the Jr. Liars Club of which Lois Kent's niece Susie Tompkins was a champion member.  Her honesty was challenge when aliens reached out to her for help and she had to overcome her reputation for fiction to get anyone to listen (Superman Family #199).

Liar's Club existed on Earth-Two until at least the 1950's.  Whether they persisted or fell out of favor in more modern times is unknown.