Collective intelligence systems (CIS), such as wikis, social networks and content sharing platforms, have dramatically improved knowledge creation and sharing at society level. There is a trend to exploit the stigmergic mechanisms of CIS also at organization/corporate level. However, despite the wide adoption of CIS, there is a lack of consolidated systematic knowledge of the architectural principles and practices that underlie CIS. Software architects lack guidance to design CIS for the application context of individual organizations. To address these challenges, we contribute with an architecture framework for CIS, aligned with ISO/IEC/IEEE 42010. The CIS-AF framework provides guidance for architects to describe key CIS elements and systematically model a CIS that is well-suited for an organization´s context and goals. The framework is grounded in an in-depth analysis of existing CIS, workshops and interviews with key stakeholders, and experiences from developing a prototypical CIS. We evaluated the architecture framework in two cases in industry setting where CIS have been designed and implemented using the framework. Resultsshowthattheframeworkeffectivelysupportsstakeholders with providing a shared vocabulary of CIS concepts, guiding them to systematically apply the stigmergic principles of CIS, and supporting them with kickstarting CIS in their organizations.