This is a list of confirmed famous people who were or are bisexual: people who have had sexual relations with, or have expressed sexual attraction to, both sexes. The historical concept and definition of sexual orientation varies and has changed greatly over time. A number of different classification schemes have been used to describe sexual orientation since the mid-19th century, and scholars have often defined the term 'sexual orientation' in divergent ways. Indeed, several studies have found that much of the research about sexual orientation has failed to define the term at all, making it difficult to reconcile the results of different studies. However, most definitions include a psychological component (such as the direction of an individual's erotic desire) and/or a behavioural compon