Information system (IS) innovation can be defined as a novel organizational application of digital computer and information communication technologies (ICT). This paper discusses how modalities of applying ICT technologies in their form and scope exhibit radical breaks, which are introduced herein as ‘disruptive IS innovations’. This notion of disruptive IS innovation is developed by drawing upon and extending Swanson's (1994) theory of IS innovation as well as the concept of radical innovation. Disruptive innovations strongly influence the future trajectory of the adoption and use of ICT in organizational contexts and make the trajectory deviate from its expected course. In doing so, these disruptive innovations distinctly define what an IS is and how it is deployed in order to address current and future organizational and managerial prerogatives. Such changes are triggered breakthroughs in the capability of ICT that lead to the revision and expansion of associated cognitive models (frames) of computing. Disruptive IS innovations are those that lead to changes in the application of ICT that are both pervasive and radical. The pervasive nature implies that innovative activity spans all innovation subsets of the quad‐core model of IS innovation introduced herein. Innovation types include: IS use and development processes; application architecture and capability; and base technologies. Radical in nature, disruptive is innovations depart in significant ways from existing alternatives and lead to deviation from expected use and diffusion trajectory. This paper demonstrates the importance of a concept of disruptive IS innovation by investigating how changes triggered by internet computing (Lyytinen et al., 1998) meet the conditions of a disruptive IS innovation defined herein. The analysis also affirms both the pervasive and radical nature of internet computing and explains how internet computing has fundamentally transformed the application portfolio, development practices and IS services over time. The analysis demonstrates that, with the concept of disruptive IS innovation, we can fruitfully analyse ‘long’ waves of ICT evolution – an issue that has largely been overlooked in the IS community. On a theoretical plane, the paper advocates the view that we need to look beyond linear, unidirectional, and atomistic concepts of the diffusion of IS innovations where innovative activity takes places in a linear fashion by oscillating between small technological innovations and small organizational innovations. In contrast, IS innovation can exhibit fundamental discontinuity; we need to theoretically grasp such disruptive moments. The recent influx of innovation, spurred by internet‐based technology, offers one such moment.