Today’s global competition and public pressure have prompted the public sector to focus on innovation as a means of improving productivity and performance. Interest in public sector innovation has been driven by: (a) political, socio-economic, environment, and technological forces, such as citizens’ expectations of better government utilisation of public resources and increased productivity; (b) increasing demand for greater choice and quality in public services and the availability of new technologies; (c) changing societal demographics including aging populations and immigrants; (d) the global financial and economic crisis. Innovation is considered to be a sine qua non to improve government efficiency and effectiveness and respond to citizens’ increasing demands for better services. However, research investigating innovation has mainly been derived from private sector contexts. It is also important to understand how socio-psychological processes provide practical ways to manage innovation within the complex social systems that exist in public sectors. Within public sector contexts, there are still gaps in the literature on the influence of socio-psychological factors on workplace innovation and career satisfaction. Related to this is the need to provide empirical evidence regarding the key factors that impact workplace innovation and successful workplace innovation practices which can lead to increased career satisfaction. Another key factor to be considered is that in Australia, administrative reforms over the last three decades have had significant ramifications on the number of engineers in the public sector. Of these reforms, competition policy, privatisation, contracting out, and commercialisation have impacted engineers. For example, an emerging body of evidence indicates a significant decline in the number of professional engineers in the Australian national, state, and local government sectors. The shortage of engineering professionals poses a critical problem for most public services. In a recent survey of engineers employed in the Australian Public Service (APS), it was found that one of the most common departure reasons among those engineers who indicated that they would leave their agency in the next two years was a lack of opportunities to work on innovative projects. Engineering professionals cannot utilise their full capabilities if innovation in the occupation is not facilitated. No study to date has focused specifically on the innovation process for engineering professionals in the APS. This study aims to fill this gap in the innovation literature by exploring the relationships through which socio-psychological factors affect workplace innovation and career satisfaction. Understanding these complex relationships within the context of the APS will help management to design strategies for recruiting and retaining a high performance engineering workforce by fostering a climate for innovation in the public sector workplace. To achieve the research aim, a conceptual model was formulated to study the influence of two climate for innovation constructs, namely leadership for innovation (LFI) and ambidextrous culture for innovation (ACI), on workplace innovation (WIT) and career satisfaction (CSF). To verify the conceptual model, a sequential mixed methods research design was implemented with the quantitative approach conducted first followed by the qualitative approach. For the first model of the quantitative approach, structural equation modelling (SEM) was conducted to investigate the causal relationships among the conceptual model constructs. The structural model indicated that leadership for innovation and ambidextrous culture for innovation influenced workplace innovation which, in turn, improved career satisfaction. Moreover, the modelling revealed a significant relationship between ambidextrous culture for innovation and career satisfaction. This study also investigated mediation effects, which revealed both simple and sequential mediation paths in the model. It was found that improving workplace innovation and career satisfaction through the recognition of an engineer’s contribution to their agency would assist in retaining and advancing in-house engineering expertise. This structural model could be used to address current shortages of engineering professionals in Commonwealth of Australia departments as the findings emphasise the importance of Commonwealth departments providing opportunities for their engineers to engage in creative and innovative projects which enhance their professional career. The second model of the quantitative approach used the theoretically based and empirically validated model from the first phase SEM to develop a Bayesian network (BN) at the factor level. The focus of the BN was to examine the impact of leadership style and organisational culture on workplace innovation and career satisfaction in the APS. Using scenario analysis, the best combination of managerial actions to enhance APS career satisfaction was determined. The results emphasise the benefit of encouraging management to adopt a transformational leadership style and instilling innovative culture in their organisation. In addition, innovative culture was a key driver of workplace innovation, which served to improve the career satisfaction of APS employees. By applying this integrated research approach, this study identifies causal relationships among factors that affect workplace innovation and career satisfaction. Finally, qualitative thematic analysis was conducted to identify common themes from archival records related to innovation in APS. These documents consisted of transcripts from senior manager presentations at Innovation Month seminars from 2014 to 2018 and other related official documents. As this empirical study addressed innovation from leaders’ perspectives, reflecting upon their past experiences and analysing themes within archival records helped to gain insights on how they regard an innovation agenda for the APS. The thematic analysis was used to identify the key drivers and barriers to innovation. Synthesis of these factors provided important insights for senior APS managers on how they could enhance their organisations’ ability to innovate in order to respond to digital disruption challenges and opportunities.