In recent years psychosocial studies have given a growing attention to online intergroup contact in reducing prejudice. Nevertheless, there is still a lack of evidence on processes that could mediate this relation. The present study aimed to fill this gap. Focused on intergroup relationships between people with different sexual orientations, it examined whether and to what extent identity processes-i.e., sexual identity commitment and exploration-mediated the relationship between online intergroup contact and perception of mediated and vicarious sexual online discrimination on Facebook. Data was collected with a sample of 357 Facebook users (M-age = 26.07, SD = 8.37; females: 64.9%, males: 35.1%) who completed an online questionnaire. A full Structural Equation Modeling was tested. Results showed that: (a) Online contact was positively associated with perceived online sexual discrimination; (b) online contact was positively associated with identity exploration but not commitment; (c) exploration-but not commitment-was positively associated with perceived online sexual discrimination; (d) sexual identity exploration-but not commitment-mediated the relationship between online contact and perception of sexual discrimination, increasing the positive effect of contact on perceived discrimination. Limitations and directions for future research were discussed.