Background Participatory research (PR) involves engaging in cocreation with end users and relevant stakeholders throughout the research process, aiming to distribute power equitably between the end users and research team. Engagement and adherence in previous workplace health promotion (WHP) studies have been shown to be lacking. By implementing a PR approach, the insights of end users and stakeholders are sought in the co-design of feasible and acceptable intervention strategies, thereby increasing the relevance of the research. Objective This scoping review aims to explore, identify, and map PR techniques and their impact when used in office-based WHP interventions designed to improve physical activity (PA) or reduce sedentary behavior (SB). Methods The reporting of this scoping review followed the PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews). A systematic literature search of 5 electronic databases—Web of Science, PubMed, Scopus, Google Scholar, and OpenGrey—was conducted, searching from January 1, 1995, to February 8, 2023. In total, 2 independent reviewers first screened the retrieved articles by title and abstract, and then assessed the full texts based on the inclusion and exclusion criteria. The search strategy and eligibility criteria were developed and guided by an a priori population (office-based working adults), intervention (a PA WHP intervention that took a PR approach), comparison (no comparison required), and outcome (PA or SB) framework. Data were charted and discussed via a narrative synthesis, and a thematic analysis was conducted. The included studies were evaluated regarding the degree of end user engagement throughout the research process and power shared by the researchers, using Arnstein’s ladder of citizen participation. Results The search retrieved 376 records, of which 8 (2.1%) met the inclusion criteria. Four key strategies were identified: (1) end user focus groups, (2) management involvement, (3) researcher facilitators, and (4) workplace champions. The degree of engagement and power shared was relatively low, with 25% (2/8) of the studies determined to be nonparticipation studies, 25% (2/8) determined to be tokenistic, and 50% (4/8) determined to provide citizen power. Conclusions This review provides a foundation of evidence on the current practices when taking a PR approach, highlighting that previous office-based PA WHP studies have been largely tokenistic or nonparticipative, and identified that the end user is only engaged with in the conception and implementation of the WHP studies. However, a positive improvement in PA and reduction in SB were observed in the included studies, which were largely attributed to implementing a PR approach and including the end user in the design of the WHP intervention. Future studies should aim to collaborate with workplaces, building capacity and empowering the workforce by providing citizen control and letting the end users “own” the research for a sustainable WHP intervention. International Registered Report Identifier (IRRID) RR2-10.1136/bmjopen-2021-054402