#19: Marilyn Monroe (1959–1961 Brief Affair)
Frank Sinatra and Marilyn Monroe’s relationship began around 1959, following the collapse of Marilyn’s marriage to playwright Arthur Miller. The two had known each other socially for years, but their romantic involvement intensified during Marilyn’s most emotionally vulnerable period.
Her beauty and fragility reportedly smote Frank, and he offered a level of stability and protection she lacked. He invited her into his inner circle and even gifted her a dog named Maf. Though neither publicly confirmed the romance, close friends noted the affection and companionship.