Purpose: Online knowledge sharing is a critical process for maintaining organisational competitive advantage. This paper aims to develop a new conceptual framework that investigates the moderating impacts of innovation on self-efficacy, extrinsic and intrinsic rewards on employees’ online knowledge sharing behaviour in public and private sector companies. Design/methodology/approach: This research analysed 200 responses to test the moderating effects of organisational innovation on the relationship between self-efficacy and rewards and online knowledge sharing behviours. The analysis was carried out using component-based partial least squares (PLS) approach and SmartPLS 3 software. Findings: The results reveal that self-efficacy significantly affects online knowledge sharing behaviour in firms, regardless of the organisation type. Extrinsic rewards encourage employees in private companies to share knowledge online, whereas intrinsic rewards work effectively in public companies. Additionally, the study found the moderating role of organisational innovation in examining the relationship between rewards and online knowledge sharing behaviour. Research limitations/implications: Future research may consider different dimensions such as knowledge donating and collecting behaviours as well as motives, such as self-enjoyment, reciprocity or social interaction ties, which may be investigated to get a deeper understanding of online knowledge sharing behaviour. Practical implications: Firms must tailor training and rewards to suit employees’ abilities and needs so as to align with organisation type and innovation. Originality/value: The study’s distinctive contribution is the under-researched context of Vietnamese public and private sector banks for investigating the moderating effects of organisational innovation on micro and meso factors on online knowledge sharing behaviour.