Tinder is a popular mobile dating app among young adults that may be used to facilitate meeting extradyadic partners. Participants who had used or were using Tinder (n = 550) indicated that most knew somebody who had used Tinder to meet extradyadic partners, and several participants reported that their own infidelity had been facilitated by Tinder. Participants were varied as to whether Tinder was an effective method for meeting extradyadic partners. Sociosexuality and intentions to engage in infidelity were associated with having used Tinder to engage in infidelity. Gender was not significantly associated with using Tinder to meet extradyadic partners when sociosexuality and intentions to engage in infidelity were also included in analyses.