Mindful parenting programs are effective in reducing parenting stress. More efficient offerings may increase accessibility. The current single case study aimed to determine the feasibility, acceptability and initial effects of a brief, online mindful parenting program. Six parents, recruited from the community, completed a 4-week online mindful parenting program (Two Hearts). Feasibility and acceptability were assessed by participant program evaluation, retention, engagement with program materials (i.e., videos), and home practice. Parents completed primary outcome measurements of parenting stress, and general distress, at pre- and post-intervention, and 4-week follow-up. Individual level reliable change index and clinically significant change were calculated for outcome measures. All parents were retained through the study; all participants reported obtaining something of lasting value from the training. Program adherence varied over time. At post-intervention, four parents reported 40-50 minutes practice per week; two parents reported 10-15 minutes practice per week. At follow-up, 50% of parents reported 30-50 minutes practice per week. Three parents showed a reliable reduction in parenting stress; two of these parents demonstrated clinically significant change. Improvements in parent general distress were indicated in half the sample. Two parents experienced a clinically significant increase in parenting stress and/or general distress. In conclusion, the Two Hearts program demonstrated good acceptability, and may be a feasible and effective program for some parents. Program adherence and dosage require further investigation. The role of acute stressors (e.g., COVID-19) must be also considered.