Frank Sinatra, Jr. (born January 10, 1944) is an American singer.

Frank Sinatra, Jr., has always existed in the shadow of his far more famous father, Frank Sinatra, Sr. Whether he is genuinely talented in his own right has been widely disputed. His supporters feel that if he had been born with another name that he could have achieved quite a following of his own, while his detractors have always claimed that he has made his entire career off of his name. Unlike his sister Nancy, he has never had a major hit recording.

Frank Sinatra, Jr. was kidnapped in 1963 and released two days later after his father paid out the $240,000 ransom demanded by the kidnappers, who were later captured, prosecuted, convicted, and sentenced to long prison terms. In order to communicate with the kidnappers via pay telephone, as per their demands, the senior Sinatra carried a roll of dimes with him throughout this ordeal, which became a lifetime habit (in fact, he is said to have been buried with a roll of dimes, along with a pack of Camel cigarettes and a flask of Jack Daniel's). Frank, the junior Sinatra, did not seem to be overly scarred by this event, as the victims of kidnapping often are. The kidnapping has been later explained in Act Three of the "Plan B" episode from the radio narrative show, This American Life by Barry Keenan, one of the kidnappers.The kidnapping is portrayed in the 2003 made-for-TV movie Stealing Sinatra , which is based on Barry Keenan's story.

Frank Sinatra, Jr. has played at times in Las Vegas in the footsteps of his father; however this seemed to invite almost invariably negative comparisons. Upon watching the act, Malcolm S. Forbes, Sr. remarked in his magazine, "Junior sure ain't Senior!", to which several readers wrote to ask if he would like his son, Steve Forbes, to be referred to in this manner.

In recent years, Frank Sinatra, Jr., has maintained a lower profile; his last major notable public appearance seems to have been around his father's death, as well as a recent guest spot playing himself on The Sopranos.