Sexual identity is how one thinks of oneself in terms of to whom one is romantically and/or sexually attracted. Sexual identity may also refer to sexual orientation identity, which is when people identify or dis-identify with a sexual orientation or choose not to identify with a sexual orientation. Sexual identity and sexual behavior are closely related to sexual orientation, but they are distinguished, with identity referring to an individual's conception of themselves, behavior referring to actual sexual acts performed by the individual, and sexual orientation referring to romantic or sexual attractions toward persons of the opposite sex or gender, the same sex or gender, to both sexes or more than one gender, or to no one.

Historical models of sexual identity have tended to view its formation as a process undergone only by sexual minorities, while more contemporary models view the process as far more universal and attempt to present sexual identity within the larger scope of other major identity theories and processes.