X-ray transients are among the most enigmatic objects in the cosmic sky. The unpredictability and underlying nature of their transient behaviour has prompted much study in recent years. While significant progress has been made in this direction, a more complete understanding of such events is often hampered by the delay in the rapid follow-up of any transient event. An efficient way to mitigate this constraint would be to devise a way for on-board detection of such transient phenomenon. The Athena/Wide Field Imager (WFI), with its 40’ × 40’ field of view can add some valuable contribution to this. In this work, we discuss an algorithm for the on-board detection of X-ray transients with WFI. We will also present a few test cases for the feasibility test of that algorithm on simulated Athena/WFI data. Finally, we discuss what type of X-ray transients are best suited for on-board detection from WFI, their probability of detections and the useful science that can follow.