A positive child-caregiver relationship is one of the strongest determinants of child health and development, yet many caregivers report challenges in establishing a positive relationship with their child. For over 20 years, Make the Connection® (MTC), an evidence-based parenting program, has been delivered in-person by child-caring professionals to over 120,000 parents to improve positive parenting behaviours and attitudes. Recently, MTC has been adapted into a 'direct to caregiver' online platform to increase scalability and accessibility. The purpose of this study is to evaluate the effectiveness of the online modality of MTC in increasing parenting knowledge, attitudes, and the perceived relationship with their child, and to understand barriers and facilitators to its access. Two hundred caregivers with children aged 0-3 years old will be recruited through Public Health agencies in Ontario, Canada. Participants will be randomly placed in the intervention or waitlist control group. Both groups will complete a battery of questionnaires at study enrolment and 8 weeks later. The intervention group will receive the MTC online program during the 8-week period, while the waitlist group will receive the program after an 8-week wait. The study questionnaires will address demographic information, caregivers' relational attitudes towards their infant, self-competence in their caregiver role, depression, and caregiver stress, as well as caregivers' and infants' emotion regulation. Results from this study will add critical knowledge to the development, scaling, and roll out of the MTC online program, thus increasing its capacity to reach a greater number of families. The study was registered with ClinicalTrials.gov on 15 March 2023 (NCT05770414).