A sedentary lifestyle, which is distinct from a lack of physical activity, refers to the amount of time spent sitting or lying down during the day, excluding sleep. Sitting for prolonged, uninterrupted periods carries significant health risks, such as cardiovascular disease, colon, lung, and endometrial cancers, type 2 diabetes, anxiety, and depression. These harmful effects of time spent sitting are exacerbated by low levels of physical activity and mitigated by engaging in high levels of daily physical activity of at least moderate intensity. Furthermore, frequent breaks from sitting have been shown to have a beneficial effect on health. Office workers are particularly affected by high levels of sedentary behavior. Furthermore, sedentary behavior may be exacerbated by telework, which has become widespread in recent years. Implementing interventions aimed at reducing and interrupting sedentary behavior in office settings has emerged as a public health necessity. Consequently, a growing number of studies on the effectiveness of such interventions have been conducted over the past decade. The results of these studies are summarized in this report. It aims to provide employers and other workplace stakeholders, as well as policymakers and public health professionals, with an overview of the scientifically proven effects of these interventions on sedentary behavior, workers’ health, and their productivity. The most promising intervention strategies to prioritize are also presented. Thus, the implementation of active furniture in the workplace, particularly individual sit-stand desks, should be encouraged. Strategies based on informing or motivating individuals in the workplace are highly diverse, and their effectiveness varies depending on the duration of the intervention. While certain interventions, such as simply providing information, have not proven effective in reducing time spent sitting, others—such as computer-based prompts to stand up—have been effective after several months of intervention. Some of the most promising strategies could thus be implemented, at low cost, in the workplace and in the context of telework. The ultimate goal is to encourage employers and other decision-makers in the workplace (occupational health and safety departments, employee representatives, employees) to initiate and implement interventions against sedentary behavior by providing them with evidence from the scientific literature showing that these interventions can reduce sedentary behavior and improve employees’ health and well-being without reducing their productivity.