The paper addresses the importance of Open Science for the Social Sciences and Humanities (SSH), highlighting the role of a distributed research infrastructure like OPERAS in advocating for Open Access publishing models. Furthermore, the paper discusses the importance of the SSH in Open Science, showing how Open Science itself benefits from considering and accommodating the needs of researchers from different disciplinary backgrounds. While OPERAS does not endorse a specific Open Access publishing model, the infrastructure partners advocate for publication processes that can meet the present demand for Open Access, transparency, and open source tools in scholarly communication. This document is intended for all stakeholders actively involved in Open Access in the SSH. This includes publishers and publication platforms as well as libraries and infrastructure providers. However, the White Paper ultimately focuses on advocacy targeting researchers at different career stages. In order to support stakeholders in advocating for Open Access, the White Paper presents the benefits of Open Access publishing for scholars, while also addressing common concerns in the SSH research community. These include, but are not limited to, reputation, research evaluation, financial issues, a general lack of information, intellectual property rights and other legal concerns, and the availability of Open Access publishing models. This White Paper draws on experiences from OPERAS partners to illustrate researchers’ concerns and to develop a guide with FAQs and solutions to address these issues. The White Paper concludes with advocacy suggestion sheets tailored to different stakeholders involved in Open Access in the SSH.