Young adults experiencing psychological distress are susceptible to poor oral health through a range of social, cognitive, and biological processes. Despite the considerable social and personal impacts of poor oral health, only limited attention has been given to understanding the factors that influence enactment of oral health behaviours and in developing interventions to improve oral health behaviours in this population. This file contains data from two related studies. The first was a psychometric investigation of the newly developed Scale for Oral Health and Mental Illness - 14 item version (SOHMI-14). The second was a pilot investigation comparing the efficacy of two brief, online interventions (education and education with motivational interviewing components) to an active control condition (hand hygiene). Participants were 152 young adults (aged 18-25 years) experiencing moderate or greater psychological distress. Over three time-points (baseline, post-intervention, one-week follow-up) participants provided data related to: the SOHMI-14 and original item pool for the scale; oral health knowledge; psychological distress; oral health behaviours; expected social outcomes; oral health values; assertiveness; social desirability; internal locus of control related to oral health behaviours; and oral health intentions. All demographic data has been removed from the dataset to help preserve the anonymity of participants.