The benefits of participating in regular physical activity are wide-ranging and well-accepted globally, yet physical inactivity is increasing, especially amongst adults. Occupations involving sedentary behaviour are considered a leading contributor to the inactive lifestyle responsible for many health-related problems. An increasing number of occupations involving predominantly sedentary work and the incidence of work-related health issues is becoming more prevalent, with evidence suggesting that adults spend approximately 60% of their waking time at work. Moreover, higher educational institutions are arguably one of the predominant sources of influence on society and can play a significant role in developing the nation and changing attitudes. Despite this, research in physical activity, sedentary behaviour, health and wellbeing substantially lacks in these settings. Therefore, this thesis adds to the limited knowledge about physical activity, sedentary behaviour, health and wellbeing interventions on university employees in the workplace. To elucidate this, several studies were conducted to evaluate existing physical activity levels and sedentary behaviour, followed by the exploration of barriers to physical activity amongst employees. The outcomes of these investigations contributed to the subsequent design and implementation of five physical activity, health and wellbeing interventions within the university. The five interventions were: • Accessibility and the availability of exercise resources in the workplace • Reducing sitting time through sit and stand workstation amongst university employees • Exploring the impact of seated, standing and walking meetings in the university setting • Getting university employees on the stairs: The impact of points of decision prompts • Promoting PA amongst employees through the 10,000 steps team-based competition Findings concluded that there is potential for physical activity, sedentary behaviour, health, and wellbeing interventions to be extended to other settings to promote physical activity engagement, reduce sitting time, and improve employees health and wellbeing. For instance, findings of intervention one indicate, employees engaged in 1287 minutes of physical activity/exercise throughout the intervention period and staff reported positive mood, work productivity and stress relief by having access to the exercise resources in the workplace. The intervention two findings indicate that having access to the height-adjustable sit-stand workstation resulted in sedentary behaviour reducing from 1974 to 821 minutes. Standing time increased from 439 minutes to 923 minutes across the week. The results of intervention three demonstrated that staff indicated enhanced anger, fatigue, tension, and vigour post seated meeting instead of standing and walking meetings. The outcomes of this thesis demonstrate that these interventions can be generalizable and physical activity, sedentary behaviour, and health-related interventions must be tailored to the needs of employees in other settings. The intervention four results demonstrated that 84 participants noticed the banners, 54 were influenced to take the stairs, 68 felt physical, and 66 felt mental benefits of taking the stairs, whilst 88 suggested that the banners displayed in the workplace will influence them to take the stairs in future. Intervention five showed that the daily average steps increased from 5959 to 10308, and staff reported motivation, competitiveness, enjoyment, active and behaviour change due to 10,000 steps challenge intervention. These findings support the implementation of physical activity, sedentary behaviour, and health-related interventions across settings. This thesis contributes to the existing knowledge of behaviour theories, including the Trans-theoretical Model, Self-determination theory and Social-Ecological Model in the subject of exercise psychology associated with public health, physical activity, sedentary behaviour, health, and wellbeing of employees in the university workplace.