What was the name of Frank Sinatra's inner circle of entertainers?

Frank Sinatra’s inner circle of entertainers was known as the Rat Pack.

The name originally referred to a broader group of actors, singers, and Hollywood friends who gathered around Humphrey Bogart and Lauren Bacall at their Holmby Hills home in Los Angeles during the late 1940s and early 1950s. Frank Sinatra was one of the prominent members of that original social circle.

By the late 1950s and early 1960s, the term had become closely associated with a smaller entertainment group led by Sinatra. Its best-known lineup included Dean Martin, Sammy Davis Jr., Peter Lawford, and Joey Bishop. They performed together in Las Vegas and appeared in films such as Ocean’s 11 and Sergeants 3.

The membership was informal and changed over time, so the Rat Pack was never a fixed club with official cards or rules. “The Brat Pack” is a separate nickname for a group of young actors associated with 1980s films, not Sinatra’s circle.