The transformation of healthcare delivery has inspired more people all around the globe to seek health information online. This study investigates the factors influencing online health information seeking activity among Malaysian millennials, particularly in the aftermath of COVID-19. This study employs a quantitative, cross-sectional research design based on a combination of the Comprehensive Model of Information Seeking (CMIS) and the Information Adoption Model (IAM), aimed to investigate the relationship between personal characteristics, health-related factors, information and source quality. The data revealed that the majority of Malaysian millennials use search engines to get health information only when it is absolutely required. Furthermore, the primary motive for seeking health-related information focused around therapy and medicines. The salience of health problems, high quality argument, reputable source of information, and perceived usefulness of information were all significant predictors of online health information seeking behaviour (OHISB). However, there were no significant correlation between demographics, direct experience, and personal beliefs with OHISB. Furthermore, this study found that information usefulness plays an important mediating role in strengthening the link between salience, argument quality, and source trustworthiness towards OHISB. This study, which focuses primarily on millennials may restrict generalizability to other generations and cultural contexts. Social bias from selfreported surveys might potentially have an impact on the findings as well. Despite these limitations, the novel and fresh viewpoint of this conceptual framework and the insight provided, may be utilised as a stepping stone for future studies to be undertaken in the digital health context. Finally, this study aids various stakeholders to further understand the nature of Malaysian millennials' online health information seeking behaviours in this present digital age.