Introduction: Partners and children of individuals with alcohol use disorder (AUD) present impaired quality of life and mental health, yet seldom seek or participate in traditional supportive interventions. Engaging the parent/partner without AUD in treatment is a promising way of supporting behavior change in both the child and the parent with AUD. Universal parent training (PT) programs are effective in increasing children´s well-being and decreasing problem behaviors, but have yet to be tailored for children with a parent with AUD. Community reinforcement approach and family training (CRAFT) programs are conceptually similar, and aim to promote behavior change in individuals with AUD by having a concerned significant other change environmental contingencies. There has been no study on whether these two interventions can be combined and tailored for partners of individuals with AUD with common children, and delivered as accessible, online self-help. Methods and analysis: N=300 participant who share a child showing mental health problems with a person with AUD, but do not present AUD themselves, will be recruited from the general public and randomized 1:1 to either a four-module, online combined PT and CRAFT program, or a psychoeducation-only comparison intervention. Primary outcome will be the child’s mental health. Additional outcomes will cover the partner’s drinking, the participants own mental health and drinking, the child’s social adjustment, treatment-seeking in all three parties, and parental self-efficacy. Measures will be collected pre-, mid- and post-intervention, and three times during a two-year follow-up period. Data will be analyzed using mixed effects modeling. Trial status: This trial is currently recruiting.